jandyman but I think that sometimes people get a little crazy about getting low latency. I'm happy with computer based systems that can achieve 5 mSec base latency.
unfortunately i think this is only partially true. my experience as a musician is different. first and foremost if you play a "real" instrument like a bass or a guitar for example you get tactile feedback and vibrations from the instrument itself, and if it is an acoustic instrument even sound. this makes latency compensation easier for the brain. if you play on a synth though and only hear the sound, low latency is much more important (at least for me)
another example would be in the studio. a latency above 2ms on the headphones is not possible for me and many musicians i know.
so it really depends on the instrument and the circumstances. and it is one of the nicest experiences to play a synth with very low latency and getting the impression that the instrument is reacting immediately, it feels much more natural then with a little latency...
so let's go crazy about low latency :-)