Yep, grounding is important too
Seriously, my unconfirmed impression (it might be unconfirmed but I make decisions based on it) is that once you get past 24 bit / 96 KHz there isn't really anything more to be had by going further... and that if something like 20 bit / 60 KHz existed that would probably be just as good...
I like 24 bit rather than 16 so I don't have to be as paranoid about recording levels, and 96 KHz rather than 44.1 because I had enough bad experiences with early CDs and poor filtering before A/D conversion to ever really trust 16/44.1 again.
