Ball bearing turbos spool better than a same size non ball bearing turbo.....period. Granted, when power braked and launched with boost, there is little to no difference, but from a low rpm punch, the BB turbo will spool quicker. This makes it more streetable in my opinion. There are lots of ways to get a big turbo to spool up, but the trick is to keep it streetable. GNVAIR, You can't possibly argue that ball bearings HINDER this cause can you? Less friction=smoother, easier spool up. Here is my experience and basis for my argument. I won't go into the long build up history of my car, but here are the pertinent facts. I ran a pte-51 with a 3000-3200 stall 16930 non-lock up 9" AC converter and a bunch of other modifications. It ran very well, no complaints. But, in order to run fast I needed lots of boost. I basically swapped in a T66 ball bearing P-trim turbo with no other mods at that time, with the idea that I would be able to keep good spool up, but be able to run less boost (pump gas) and still get good times on the street (where high boost without alcohol or race gas is detonation prone). I have sacrificed ZERO spool up issues with this much larger, ball bearinged turbo. I have also made an 11.72 pass at nearly 116mph with 18 degrees of timing and only 15 lbs of boost. Yes bigger wheels are more efficient at higher boost levels, but they certainly work well at lower boost levels also when the combo is right. There are 3 important things that make a fast buick streetable....the combo, the combo and the combo. Saying that using Turbonetics turbos is a bad idea because they haven't done enough research on our engine specifically is short sighted and doesn't really make sense. The technology available for our cars keeps growing, don't bad mouth new thinking because you don't want to change your own combo (GNVAIR). I get 22 mpg on the highway and have the ability to run mid to low 11s on pump gas with no alcohol or race gas, and have no spool up issues. This is with a "big" turbo.........come by and I'll let you drive it, you'll see.