yes. a 20g, in subie terms, is a pretty big turbo, since their motors dont like boost. my buddy is right on the edge, the guy who tuned it would NOT upp the boost any more, and already said the 18psi he was at was pushing it and doesnt expect the motor nor tranny to last very long if hes got a heavy foot.
i think the stock turbos are very small, the wrx is even smaller than the STi's. going from a mini stock wrx to a 20g is like a huge step.
though a 20g is old news in the evo/dsm community, most of them go right up to the 50trims that are better and equal or cheaper price depending on turbo options(ball bearing, clipped/ported, etc).
wrx are not much slower than a STi. IMO the only thing that i see different is they got a slightly larger turbo, a VF39 (which is still weak compared to other cars stock snails, like the Evo8 twin scroll 16g which can do 25-28psi efficiently and support upwards of 400-450hp), 6speed tranny that can handle more abuse but still nothing to brag about, and better suspension, and a bit better top mount intercooler(its thicker, thats about it).
Coming from someone how actualy drives a Subie car
everyday.I think it will be a drivers race.I know what the
03-04 STI's are capable of and if he can't drive or launch you will win.If you screw up your launch you will
get owened off the line.With all things equal drives race.
Go to the track and fine out.