So I'm going to do a compression test tomorrow and see what's really going on there. Ultimately I think the ringlands are shot. I've read the only thing holding the STi back under about 450hp is the pistons. I'm not too concerned about noise differences from the stock pistons. I'd actually prefer a sound change. I'm just looking to see what are the best out there and what they would cost, and what other comparable products cost. Any advice would be great, thank you!