Got the thing installed today, took about 6 hours. I'm sure I feel a SOP power improvement but the more aggressive sound makes it hard to tell how much. Install was pretty easy, I did have to cut a tab off of the trans cross member, modify the piece that bolts up under the the back of the Ypipe and one of the factory plug boots is touching the header pipe. Next week I'll do the Dyno stuff and may even do some tuning. I'll post results.