How does it rank among pre-amps and A/D convertors??
Right now I have a UA-5 busman mod and was wondering is it worthwhile to sang one for a good price?
That question is suspect to opinion, as everyone here as there favorite. However, I will give you my 2 cents since I have owned several modded ua-5's, own a minime, owned other pre/ad's, and played extensively with Grace boxes.
The converters in the minime are top notch. As for the pre, I really dig it. Some do, some don't. It is definitly all apogee. Full bodied with it's own distinct character. One thing I've noticed, apogee owners tend to stick with apogee products. Same can be said for Grace owners. Just depends on YOUR EARS. For me, I don't like Grace boxes, hence why I own the minime for my 2 channel needs. That's my ears. Others like Grace, and not Apogee, that's what their ears tell them.
My advice, if you can, borrow one and run it for a bit and see if you like it. Or match your mics to the minime in a archive search and listen and see what your ears tell you.
As for a change from your modded ua-5, this would most definitly be a step up in quality, both build and sonic characteristics.