I was going to do dual infinite baffle subs with four of those in our HT, but then my microscopic attention span moved on to something else and ... ooh, shiny!
It depends on things like the type of towers nearest your home, the backhaul capacity available etc. So actual performance on any given network is highly site-specific.
Haven't tested it, but the manual for my Ayre DAC suggests that, for best performance, it should be run on a USB bus that is not being shared with any other devices. I have seen Gordon Rankin arguing the same on AA and CA, but can't recall the technical specifics.