Just hit this one up on JKO, but I'll hit you here, too
Got one of these with my Superchips. It wasn't in stock, so I had my Superchips on for 2 weeks before I got it. Had it for 3 weeks, just sold it online. Junk. The only thing it added was a whistling sound. No MPG improvement (no noticable difference over 0.1-0.2 MPG, which can be chalked up to weather, driving style, etc.), no power gain- as I said on JKO, I've been building hot street and race cars since I was a behbeh- my butt dyno is pretty darn sensitive, and I felt zero, zip, nada. Just heard an annoying whistle.
While you MAY see a little gain without the reflash, this simply isn't worth the $ on the 3.8, in my opinion. Mark W.