Very foolish questions.

[belligerentruth]

Ok, I admit to being a total newbie, that being said here are my questions:

What's the difference between an Xmag and an Emag?

Pnuematics - are these only good in full mechanical guns? Or do they have a place in E/X mags (one, or both?). Next what do they REALLY do? Trigger bounce, yes? They are preferable to a well-tuned ULT right?

Eyes - Are these REALLY an object of contention as to their usefulness in mags?

Lastly, if you can list some of the more common mags in order of superiority/desireability I'd appreciate it. For example I know an Xmag is better than an emag (though I'm not sure why) but how does an Xmag compare to a perfectly tuned pnuemag? I thought with trigger bounce you could really get close to a full auto (and a debateably legal full auto at that)

I guess what I'm looking for is a brief introduction into the various technologies and how they compare to one another - in as much or as little detail as people are inclined to go into.

[questionful]

Ok, I admit to being a total newbie, that being said here are my questions:

What's the difference between an Xmag and an Emag?
The E-mag is just an automag with E-mag lowers. An X-mag has a one-piece body, instead of having both a body and a rail like every other AGD mag.

Pnuematics - are these only good in full mechanical guns?
You have to understand that all automags share the same basic valve. What determines whether an automag is electric or mechanical is the trigger actuation. Pneumatics are one type of sear actuation. Usually your finger actuates the sear. In an E-mag, a solenoid actuates the sear. In a pneumag, pneumatics actuate the sear. Since pneumatics are mechanical, a pnaumag is considered mechanical. However, if you use a solenoid valve instead of just a plain solenoid, you get an electropneumatic mag, which is not considered mechanical because it uses electronics. You can put a pneumatic frame on any mag. If you want to turn an E-mag into a Pneu-mag, you remove the E-mag lowers and put on a Pneu-frame. This makes it NO LONGER AN E-MAG, and it is a mechanical pneumag.

Or do they have a place in E/X mags (one, or both?).
Next what do they REALLY do? Trigger bounce, yes?
No. It's just a system that actuates the sear for you. Normally this is done by your finger. With a pneumag, your finger actuates a valve (much easier, shorter trigger pull) and the valve actuates a ram that pushes on the sear. Look at this animation, just focus at the parts in the grip frame, those are the parts that make an automag a Pneumag:

http://www.zdspb.com/media/tech/animations/pneumag_5fps.gif

They are preferable to a well-tuned ULT right?
Do you mean is a ULT preferred over a standard RT on/off when using pneumatics? I don't think it really matters. I would think it only matters if you are an efficiency nut and want to get the lowest psi possible on your Pneu-frame's LPR.
Now, if you're asking if a pneumag is preferred over a normal mag with ULT, yes. It has a lighter and shorter pull than the ULT.

Eyes - Are these REALLY an object of contention as to their usefulness in mags?
I don't know what an object of contention is, but you don't need eyes on a mag if that's what you're asking.

Lastly, if you can list some of the more common mags in order of superiority/desireability I'd appreciate it. For example I know an Xmag is better than an emag (though I'm not sure why) but how does an Xmag compare to a perfectly tuned pnuemag? I thought with trigger bounce you could really get close to a full auto (and a debateably legal full auto at that)
Mags don't come in models really. You can categorize them, but they are an assembly of different interchangeable parts and when building yourself a mag, you choose each part. You've got a lot to learn, but don't worry; we're here to help. I know what it's like to all of a sudden be bombarded with all this info about mags, I was there recently. Just hang around AO for a while, pretty soon you'll be an expert.

I guess what I'm looking for is a brief introduction into the various technologies and how they compare to one another - in as much or as little detail as people are inclined to go into.
I suggest you first go about finding out how automags work. This will make everything else MUCH easier to understand. To start you off, there are two kinds of automag valves; Classic Valves and RT Valves. Stare at this animation until you understand it, it is a Classic Valve:

http://www.zdspb.com/media/tech/animations/automag1.gif

^^In that animation, the air goes in through the side, so you can't see the input really. It goes in from in front of your monitor, into the space right above the rear fieldstrip-screw.

Then read this to understand the RT Valve (the most awesome mechanism on the planet):
http://www.automags.org/forums/showthread.php?t=231575

Added my answers in Bold. I think I forgot some stuff, but I'm sleepy. Hope that helps you on your way to understanding mags. Welcome to your newest addiction!