my old car was basically the same as freds 05 sti with same mods and same power with the 35 hooked up.. 195kwatw..
then tried a gtps01 with mixed results.. need really high boost levels(24psi) to reach optimum operating range and this just pulled heaps of timing out.. 207kwatw..
then tried a 'rally proven' vf30 with internal/external ceramic coating and porting on several decent tuners advice and it made 200kwatw at only 18psi.. timing was fairly advanced and was probably the quickest to drive on the street and got a few more km's per tank.. the overall cost of the 30 with the ceramic coating was the same as the gtps01..
not trying to be a guru, just what experience i had with a few turbos..
now i have got rid of the rice burner and have a bf xr6 turbo ute that has 211kwatw and 420nm stock
different horses etc..