I have a pair of API 312's (A2D) and a Chandler Germanium. I've used the Germ for recording guitars and bass in the past and it is GREAT for that. Nice as a DI for drum machines and monosynths too. It can turn the 606 BD into something wonderful. My only beef with it is that there's no way to attenuate the output on the pre itself, so you have to be cautious if you're recording direct from the Germ into a convertor.
The API just sounds good with anything to me. Lately I typically record everything through the API's as I usually build up my tracks in layers so two pres is enough. If I'm recording more than two things at once I'll record the less important sounds through the Germ or the pres on my Fireface (which are great for synths as well...never used them with a mic).
The Chandler will probably be sold shortly as I haven't really used it in a while now.