I wouldn't bother with the GTWs personally, unless you can get a good price on them. They are all based on the ball bearing T-series cores, so use different T4 trim turbine wheels for the 36 and 38 series and a T3 turbine for the 34 series GTW turbos. This means they are basically the equivalent of the old gen Precision PT turbos, pre CEA turbines... the new CEA and Gen2 CEA Precisions are a better thing imho. The compressor wheels should be OK, however - still waiting for compressor maps though but don't confuse the fact that they are a new product with the fact that they could be a higher spec - they are actually aimed at being a "budget peformance" option and essentially ranked lower than the GTX range.
