What engine are you planning on putting this on? If it's a D16, the T3/T04E is going to be a bit laggy, but the .48 turbine and 57 trim compressor shouldn't be too bad. If you can find a .48 turbine and 50 trim compressor, that'd be a little better for a D16. If it's going on a B16, the .48 turbine/57 trim should be alright, but you might still want to go a little smaller. As for the ball-bearing upgrade, it costs more than the actual turbo does, so you have to ask yourself if you think it's worth the cost. Yes, it spins more freely than the traditional thrust bearing, but the cost is somewhat off-putting. If you have two turbos that are otherwise identical, except that one is ball-bearing, the ball-bearing turbo is only going to spool maybe 500rpm faster than the non-bb turbo. Is that worth doubling the price of the turbo to you? As for the polished compressor housing, that's purely cosmetic, obviously, but you can also achieve similar results polishing it yourself. Of course, if you don't want to go thru the trouble of working it with a polishing wheel, then it might be worth it to get a polished housing. In the end, it's your call, but I don't think the b-b upgrade is really necessary, and I could do without a polished compressor, but tha's just me.