I agree with you Polaris. There is nothing wrong with USB for smaller setups, although I wouldn't personally multitrack a drumkit over USB (thats just personal choice because I think firewire is more reliable).
Anyway, who monitors through a computer anyway, you want to monitor straight off your interface while recording - then you get absolutely NO latency.
This whole USB latency myth is total BS, I would always prefer to use FW but USB can be just as good for certain things.
I actually do monitor back through the computer often. Generally when I am running a guitar dry into the interface, then using Native Instruments Guitar Rig 3. You've got to, otherwise all you here is plain dry guitar.
Also, I frequently use convolution impulses to mimic speaker cabs, and that needs computer monitoring too.
In both cases, USB does fine.
I'm not saying FW isn't great for audio. Obviously it is. But for the other guy to say USB is useless for audio is extraordinarily ignorant, and shows complete lack of experience.