The audiophile is a hugely used card and for the most part people have great success with them. They offer 2 channels of 24/96 via unbalanced RCA connections, and 2 channels of SPDIF. No breakout box.
The Delta66 and Delta44 are essentially the same. The Delta44 provides four 24/96 channels (inputs and outputs) via balanced 1/4" TRS connectors (switchable +4/-10). The Delta66 is the same beast, but with 2 additional channels of SPDIF. They both come with a small but sturdy breakout box. They are good cards and very few problems are reported. A whole ton of people around here use them. I used a 44 for a long time and it worked flawlessly.
The Delta1010 is the big flagship 24/96 card. It offers 8 balanced 1/4" TRS ins and outs, two channels of SPDIF, a MIDI port, and an external word clock connector. The 1/4" TRS, MIDI, and word clock connectors are all in the big rackmount breakout box. The A/D/A converters are also in the breakout box, instead of on the PCI card, resulting in a lower noise floor and perhaps better accuracy, than either the audiophile or Delta44/66. I am currently using the Delta1010 and think it sounds subtley better than the Delta44 that I used to have. Let's just say I wasn't expecting any difference, but instantly heard a bunch of crap in my mixes that made me wince. Who knows, could all be mental. The only downside of the 1010 is that the 1/4" jacks are all on the rear of the breakout box, the +4/-10 switches are also on the back instead of software switchable (like the delta44/66), and the SPDIF is actually on the rear of the PCI card.
The Delta1010LT is a "light" version of the 1010, with no breakout box. All connections are made via unbalanced RCA jacks. Two channels have a switchable mic preamp and XLR connectors. I'm willing to bet that the quality of this card is more towards the Delta44/66, which really is just fine. This would be a good budget card if you need lots of I/O and can stand the hassle of connecting crap to it.
The Omni Studio is like an alternate frontend for the 44/66 cards. It has mic pres and a couple little features, which *might* make it worthwhile. However, I have heard just as many dings about the omni as I have praises...although I don't listen much. I would prefer to just buy outboard pres...easier to sell, more fun to play with.
Those are really your choices if you're looking for a PCI system. I noticed they have some kind of other crap too but I wouldn't bother.
The flying cow is just an A/D/A converter, you would still need a digital soundcard to get the audio into your machine.
Interestingly enough, all of these cards use the same drivers and the same exact control panel. You can use two or more cards together too (if your system doesn't balk). M-audio is on top of the driver game, releasing 2K and XP drivers long before many other "pro" audio manufacturers....HOWEVER, that's not saying much. For the most part their drivers are very stable. Good 2K and XP support for ASIO and WDM.
In terms of sound quality...don't sweat it until you really think that you need to sweat it. They're all good prosumer soundcard systems, and certainly meet the needs of most amature home recordists! Worlds better than something like the SB Live (which I'm also using), which isn't horrible to begin with.
I totally recommend the above m-Audio soundcards, but they're not the only game in town!!! Consider all your options.
Slackmaster 2000
