I've had my 8/24 for a few weeks now with very few complaints. However, it is limited to a max of 24-bit/48kHz (no 96). I just ran a very unscientific test with Cakewalk and Sound Forge. I recorded 2 tracks, one at a time, both roughly 30 seconds at 16-bit, 44.1kHz. The first track was with nothing plugged into the 8/24. The second was with the direct out of one of
my Mackie 1604 VLZ channels patched to the 8/24 (I set the trim and fader to unity gain, EQ section flat, with nothing plugged into the test channel). In both cases, the noise floor hovered below -72dB. This is just my current setup, YMMV.
I plan to eventually move up to 96k, but not for a while. The "cost" of 96k vs. 48k is twice the overhead, which could translate to half the track count and WILL translate to twice the storage space. 24-bit adds 50% more overhead, but I believe the benefits are worth it. I would probably have to upgrade my whole system to get the performance I want at 24/96. I weighed a lot of factors over the past couple of months, and decided to hold off on a major PC upgrade for another year or two. By that time, there should be affordable processors and drives that can sustain more tracks at 24/96 than my current system can sustain at 16/44.1. The world of multi I/O cards will probably be very different then, too.
I looked at the MOTU gear and drooled heavily. I've heard good feedback from "the trenches" and I love modular designs. I came very close to getting one. The final decision to go with the Gadget was a compromise. I picked up some other useful gear with the cash I saved, while accepting the fact that I will proably outgrow the Gadget card. Until then, there are other purchases that are likely to improve my quality more than going 96k. Once the card becomes my bottleneck and I just can't live without something better, I'll replace it.