I like the tube 44 better for guitars over the 33, as i dig the tube sound! (not my favorite for vocals though).. I like bigger upfront sound for that....

the Model 1b is awesome for vocals and my GT choice! it has a very nice "vintage type" sound. I've tried a lot of tube mics for my voice and the GT Model 1b (IMO) is the best for that vibe. guitars sound great as well (as a vocalist first its my fav)..worth checking out!

[[url=http://[/URL]="http://www.midiman…"]Groove tubes Model 1b (tube)[/]="http://www.midiman…"]Groove tubes Model 1b (tube)[/]

GT 55 is cool for toms, surdo, bass guitar cabinets. Be careful with gain, it is a little noisy compared to a C3000B, which is midish.

A fellow engineer in my studio has a gt66. He loves it. As a matter of fact I'm going to try it out today on tracking male rock vocals. I usually use a Neumann tlm103. I'll post again on how it goes.

what are the differences between the gt55 and the gt66? more patterns?
I imagine the GT55 shall sound nice in female sopranos or voices lacking some bottom around 120/250.
For a baritone voice I would not recommned it. It will end up considerably boomy.