Long story short - yes, I think the B&M is a better buy:
-IMO feels tighter than the UUC that I had in my E90
-Much easier install
-Reuse of plastic ball shell is flimsly at best
-Not height adjustable
-With the B&M in the shifter sits just a little canted to the right
-Both of these products could use a little more engineering: The UUC calls for 6 tiny screws that are susposed to be loctite'd in place. If you can pull this off without filling down one of your allen wrenches let me know how. The B&M reuses the plastic shell which would could out of its place relatively easily.
-After driving around for a couple days, I havent had any issues with the B&M coming up and out. Plastic rubber boot might help with that. As long as you dont jerk up on the shifter wont be an issue.
-B&M feels tight- very tight, and very mechanical. Youll be shifting during strong acceleration and think you missed a shift short, but then youll realize your in 2nd, 4th or 6th, and the throw is just shorter. With the UUC sometimes I would feel a shift would have 2 notches, as in when I went from N to 2nd there was a click click. With the B&M I dont seem to have that issue.
-BLAFE (bottom line at the f end) Both of these mods are worth is and really make the car feel like it should, nimble, precise, and predictable. With the SSK I can push her hard up to a curve, hit the brakes and pull off a heel toe without having to worry about the shift. With the CDV, during slow traffic you have the ability really control your movement without the jerkiness, i.e. 5 mph or less.