I've gotten very interested lately in PnP'ing my stock TD04 in my WRX. Seems (from what I have researched) that it should give a modest bump in power (10-20 whp) and, more importantly, let the turbo spool quite a bit quicker. I recently decided not to swap in a VF48 into my car due to high miles and fairly high cost (~$2k)... sounds like I can PnP my turbo and get a retune for it for around $300.
Anyone here have any experience with this? Are the gains noticeable?