In my previous job, I had access to a USBpre, and it's a wonderful piece of gear, provided you are not all hot for 96khz (I'm not a bat, so I think 48khz is fine.....). As for Audix 2145s I used them in a variety of sound reinforcement settings with great success. I think the Micros would be fine for just about anything calling for cardiods. -- could you budget stand the 2150s so you could switch pickup patterns?