We often hear professionals question whether USB is robust enough for serious multi-channel audio work. With the current generation of high-end USB interfaces, we definitely feel it is. For example we used an Apogee Symphony I/O connected to a Macbook Pro by USB to record eight simultaneous tracks of 96k/24-bit audio from microphones for recent sessions — no problem whatsoever!
Believe it or not, in some cases, USB may actually be faster than other protocols. According to Apogee, at 96kHz, the latency of the Symphony with USB can be as low as 0.52ms, while using the Symphony 64 card for direct connection to the Symphony can get you as low as 0.59ms.
Yes, you read that correctly; in this case USB is faster than the proprietary Symphony 64 connection! The reason is that under USB, Apogee’s low-latency Maestro software runs right on the Symphony I/O. When you use the Symphony 64 card, Maestro runs in the computer. That small difference results in USB actually being faster via USB. (Of course, the Symphony 64 card provides other features that USB can’t offer — speed/latency isn’t everything, and which is best for your situation depends on what you are doing.)