5.1 is the one for nubs aus, fyi it's only a delay on both rear speakers, and a lowpass filter for nubs without decent amps for bass so they use only one "sub", the center is also ghay because flethcher response graph dictates we hear midrange better anyways. last but not least, there is only 2 ears in your head (in case you mean AC3 5.1 and up). and george lucas sucks (he "invented" pro logic).
there is nothing better to motivate nubs than the next catastrophe: "oh noes look that nub he only got 2 speakers, I pwn him I got 6", it sells good, how else would the sound business continue ? everyone already has stereo, so the marketing department was thinking of new ways to make more money and they found it in 5.1 and the like, why stop the nubs from buying more speakers. "yah baby give me moar channel for the win", what you wrote is an excellent example of how the nubs think, more is better. and I might add, very similar to the way they think about other things as well, for example: larger operating system is better "omg check out this pwn vista it on DVD !!! whoa !"...and more expensive cars "look me I got farrari I pwn you" when in fact nobody who has this cars ever drives them anywhere near their potential... and not to mention "omg I got HD bluray 1911x1337 resultion and it has 24 bits soundz ftw !" while in fact the HDMI interface performs so many color transformations that destroy most of the quality, not to mention that people play some of this content on built-in sound cards....these kind of things have no end - they go on and on and on, that's where the money comes from for the industry so they keep on thinking and finding new ways to sell you.
ignoring position, velocity, distance and volume settings / effects
last time that was not the case, and all worked, but if it doesn't like I mentioned before, im sure modders have plans to test how it goes ingame and see, im sure a decision can be made later with testing.
I wouldn't worry too much about bandwidth disk space and RAM, especially if it gives me more quality, but if there are people who would, then maybe 2 versions of mod, but then sounds have to be in the same archive and all content must be synced so that is a major problem, but not a good idea to have such data require archive sync, all other games you can easily replace the sound (and even graphics) and you can still play multiplayer (doom3, ut2004).
Nobody will notice
like I already mentioned this before, plz speak for yourself, and hi-fi music and sounds is not crap (F.E.A.R, rFactor to name a few) it's what makes the game nub or pro, that's why they say doom3 sucks and F.E.A.R pwns because the former were worrying too much about their precious RAM, sure there is time and place for space concerns, but the price is too high sometimes, I wouldn't like a game to sound like crap just because I have no RAM, it is my decision on what to save space in memory, and it is per-system basis, some might need to and some might not, we are not here to make the decision for the users, it's easy to take sounds and compress them with a nub codec and release, but it's not at all possible to get the originals from the nub codecs, so just make archive sync not include cheat-irrelevant data and you will be happy (build menus, sounds, even textures dont have to be archive sync), and those who want to save space on sounds should just use /s_khz "22", but spring doesn't support dumbing down the sound in-game, so what now we have to be aiming for the worst from the start just because spring doesn't support any better options to dumb down the sounds ? /s_khz "22" will save you 50% of the ram instantly.
as for what reverb is good for, well, it will make it more realistic sound, even the open maps have mountains, it's just maybe too hard to code a good reverb algorithm that will be light and fast and produce good results
p.s. "compression artifacts" doesn't even begin to cover it, but to know what I mean you need...hi-fi !
and the reason that you say hi-fi is crap is because you don't have it, if/when you have hi-fi (as in NOT buying your speakers in computer stores) you will change your mind. it's just like the starcraft 2 argument going on near-by so "in-short, just don't": "starcraft 1 has a shitty interface so everyone is hyped about their precious micro", "...pro players have to compensate for shitty interface governing their gameplay...", so even noob spring players would pwn pro starcraft players with spring interface, it's all point of view.