If you have something that works for you, you may just want to stick with it. That being said, I've tried a bunch of mechanical keyboards and have been using a Kinesis Advantage for about five years: http://jakeseliger.com/2011/07/17/further-thoughts-on-the-ki... and am in fact typing on one now.

Perhaps the best recommendation I can give is simple: I'd never go back if I could avoid going back.