I've been using D7000 and Audinst MX1 with incredible satisfaction and musical bliss.
I'm looking at Nuforce icon HD, but I appreciate all recommendations within $300-500 range.
Please recommend some :)
The NFB-12 is good, but it's a matter of preference versus the Audinst. The extra power is nice, but really only needed for orthos. On the other hand, the NFB-10SE is a definite upgrade, but that's at the very top of your budget. Might want to check the used forums for one.