My impression is that once you get above 'adequate' then there's little tangible benefit from expensive BB bearings - and given you can often find Ultegra for a tenner, I'd be disinclined to pay more.
What *does* make a difference is the quality of fitting. The BB shell must be faced to allow the cups to be parallel (if there's paint on the end faces, without a circle of clean metal, it hasn't been done), and the wee plastic fitting that initially holds the NDS crank in position mustn't be overtightened, or it will preload the bearings and kill them in short order.
(In another thread, someone - Brucey I think, or maybe Tors - suggested a procedure that, from memory, was something like tightening it to about 2Nm to snug the crank into position, then back off completely and retighten to 1Nm - barely finger tight. I can't remember what they said about lube.)
Finally, the crank pinch bolts must be done up very tight.
Basically, the bearing preload must be far less than you think could possibly be adequate, while the pinch bolts should be tighter than you think is needed. With a normal size allen key, as tight as you can possibly get them, then a couple of grunts more should be about right. (Ease off a touch if you're a gorilla, mind.)
