I'm always glad to hear from people with questions and comments of any kind. But I have found myself answering many of the same questions fairly often. Here's a few, along with what I find myself answering:

Q: Can you add pickup <X> to your samples?

Q: Couldn't you just use one guitar for all pickups?

It certainly makes sense to minimize the number of variables in any test, but unfortunately it's not very practical in this case. The poor guitar that got subjected to this would have so many holes in so many different places that I shudder to think of it. And some systems (I'm thinking of the Taylor ES, not to mention Ovations and Takamine's) can't be separated from the specific guitar. And of course, if we had one guitar of Brand X with all the pickups sampled in it, someone would be asking, "but what would it sound like in Brand Y?" But I am trying to get some redundancy, with the same pickup system in different guitars, as well as different pickups in the same guitars, to get an idea how much difference the guitar does or doesn't make.

Q: Which pickup should I use in <Brand X> guitar?

I really only have experience with what I've posted here, and maybe a handful of other guitars/pickups that I've had over the years. You'd probably have better luck talking to your local guitar tech at a music store or repair shop. He or she probably installs and repairs more pickups in a wide variety of guitars every week than I've ever seen. If you're interested in putting a pickup in a custom guitar, talk to the luthier, who probably has a great idea of what works well in his or her guitars.

Q: Which pickup do you think is the best?

That's really not useful for me to try to answer. For one thing, I want to stay unbiased as much as I can while recording these samples. More importantly, my playing style and needs may be completely different than yours. "Best" is really a personal opinion, you'll need to decide for yourself, I'm just trying to give you one more tool that may keep you from having to try them all yourself. But in the end, what works for you on your guitar is all that matters, so you pretty much have to dive in a try some pickups out for yourself.

I can provide a few opinions:

Any pickup will only sound as good as your amplification

Almost any pickup can sound great through a great sound system

The pickup that sounds best on a recording may or may not be the best pickup for your live use. You may want a different sound, you may want to blend with a band, or sound bigger than life, or just to sound musical, which is not necessarily the same as accurately reproducing your acoustic tone.

At this point, I think I've heard from at least one person who has said "pickup X clearly sounds the best" for every sample on my site. So no matter which one you like, you won't be alone!

Q: So which pickup(s) do you use yourself?

Again, my style, what I like, my playing situation, and so on is probably completely unrelated to yours. For what it's worth, my personal favorite way to play is totally acoustic, and I do that if I can. My next favorite way to perform is in a good sounding room, with a good sound system and a good microphone.

Finally, if I really need to use a pickup, I tend to grab whatever guitar currently has something in it that will work, possibly whatever I last installed for a test, and I've used just about everything at various times. I've found you can't go very far wrong with a magnetic, which I can quickly stick into any guitar if I need to. They don't usually produce the most acoustic sound, but they just work. Soundboard transducers have worked well for me at low volumes, but the ones I've used seem to be best if you have some time to do some sound checks and EQing, to avoid feedback issues. I generally shy away from most under-saddle pickups, but on the other hand I think the best live sound I ever got was with a Taylor 514 and its stock Fishman Blender system. The key was that I was playing through an incredible sound system, which is the element that makes the biggest overall difference in the sound.

Q: How can I deduce from these tests which pickup will sound best in
live use?

I think that's really difficult to do, because there are so many variables, and this test doesn't begin to capture them all. For example, when I'm recording, feedback is not an issue, yet it's almost always an issue in live performance. But, there are some characteristics of various pickups that remain the same. I recently heard a player use an M1 live just after I'd made my first test recordings of it, and I immediately recognized a certain (hard-to-describe) characteristic sound of his live rig from what I'd heard on my recordings. Once you zero in on some of the distinctive characteristics of some of these pickups, you may recognize them no matter what system you play them through. More concretely, you can tell from the recording if the pickup is bright, sharp, or deep, fat or thin, if the system picks up guitar body sounds or not, and so on. Tonal differences can be dramatically shaped using EQ if needed, but you can probably get a good idea what you're starting with from these recordings and try to match the starting sound to what you're looking for. Then be prepared to experiment yourself.

One thing you might consider is to play these samples through whatever system you would normally use (an amp, a PA, etc) It won't be a perfect simulation, but it'd a lot faster and cheaper than buying them all, installing each one, and trying to compare them. I haven't tried this myself, but studios often record guitars and basses directly and send back through amplifiers (or amp simulators like AmpFarm and so on). You'd probably have best results with a direct box ro a "re-amp" type gadget (check out http://www.reamp.com ), which can help with level and impedance issues. It may be useful to download the tracks and load them into a mini-disc or MP3 player that you can plug into your system.

Q: I've listened to all the samples, and I'm still not sure what
pickup I should choose. How can I decide?

This is really a personal taste issue. But I'd start by reading the sites on my links page if you haven't already, and doing some web searches to see what else you can turn up, and then start defining your needs, perhaps in the following order.

1.  How loud do you need to play? If you're playing loud, as in a rock group, feedback is probably going to be your #1 issue, with everything else a distant second. Tonally, you probably just want to "cut through the mix". My samples  can't help you much there, and I have very little experience with this. My understanding is that magnetic pickups (Sunrise, Mag Mic, Rare Earth, etc) fare the best in this, but other systems also claim low feedback, including the Taylor ES, K&K and others. Based on my limited experience, I'd say magnetic pickups will usually have the least feedback problems, followed by undersaddle pickups, followed last by soundboard transducers and microphone setups.
   
   If you're playing softly, you probably have more choices
    
2. What's your playing style? What kind of sound are you after?
   If you play solo fingerstyle you may want a warm, rich sound with a lot of nuances (you may want a blended system). If you tap and incorporate body percussion sounds, you'll need a pickup that can pick up these sounds, either a sound board transducer or a system that includes a microphone. If you strum hard with a pick, you need a system that has lots of headroom, with minimal "quack". You might consider a magnetic, some under saddle pickups, or a soundboard transducer.
    
3. What's you tolerance for setup hassles? If you play in situations where you can tweak the sound extensively before you play, you may be able to use an elaborate custom system that combines multiple pickups, that  lets you get a great sound if you can take the time to get it all balanced and adjusted. On the other hand, if you have to show up, plug in and play, you want reliability and simplicity above all.
    
4. How good is the rest of your system? Your sound is only going to be as good as your amplification. You're unlikely to get the benefit of using some of the more nuanced pickups if you're playing through an inexpensive amplifier. If you're trying to upgrade your existing pickup sound and you don't have the best amplifier you can afford, you might be better off investing you money in the sound system instead of changing the pickup.
   
   Also, some pickups interact with guitars in different ways, so the quality of your guitar may matter. A pure magnetic pickup seems to vary the least with the guitar, and a Sunrise may sound as good on a $100 guitar as a $10,000 one. (I saw Leo Kottke playing with a Sunrise and a relatively inexpensive Martin 000-15S a while back, and it sounded 1) great, and 2) not that much different than previous times I'd seen him playing with a more expensive guitar) Pickup systems that sense the body of the guitar, like soundboard transducers and mics may be more sensitive to the natural tone of your guitar, and if that's what you're trying to convey, those systems may be worth exploring. Also consider external gear. If you use or want to use lots of effects, you may want to keep that in mind. Certain gizmo's like the Fishman Aura are best matched to certain pickups. If you have the ability to exploit stereo, a multi source system might be useful. If you have a small-mono rig, the complexity of a stereo pickup may be unimportant, (although dual source setups can still be useful  even in mono)
    
5. What's your budget? Maybe this should have been the first question. Some pickups are under $100, others can go sky high. Aside from your budget constraints, you may not want to put a $1000 setup into a $100 guitar, nor a $29 pickup in a $5K guitar as a practical matter.