broudl73, so I picked up my AP Thursday and installed it last night. MMMAAANNN!!!!! I'll say what soo many before me have said...THIS IS HOW THE CAR SHOULD HAVE LEFT THE FACTORY. Instant throttle response, actually puts you back into the seat in 2nd gear kinda like stock 1st gear would. I can't help but play with the different screens in terms of Live Data feeds. You can log(which I need to learn the proper way, if anyone is willing to fill me in) or just look at the realtime stats for just about everything. My MPG even went up by about 3-4mpg. Ok, so to answer your important questions. You can flash back to a stock map, not suggested if you have a custom tune for a full TBE. The dealer can't tell that you have an AP unless they need to do something with the ECU. I wouldn't worry too much about the waranty being affected by the accessport though. Secondly, sad to say, but the AP increases the performance and not the sound of the turbo or BPV. I had a K&N typhoon on the car which sounded amazing, but I knew that it was bad for the engine without a tune. Once my girlfriend gets my TBE, then I'll put the Typhoon back on and get in touch with INFAMOUS1. Friendly advice, and please learn from my mistakes....DON'T WASTE MONEY ON A BPV OR INTAKE JUST TO GET THE TURBO SOUND!!!!! Get the performance mods, THEN throw on the intake (even though it's not needed) Intakes are easy to find second hand on here. What year is your LGT again? All in all, I'd definitely recommend the AP. Yes it costs ALOT more money than going Opensource, but for me, I have an 8 month old and work 10 hrs a day so time is not readily avail to log and tune through OS. Matter of fact, I need to run to the store before they stop selling beer. *Note that you will find every excuse to drive your car* On a side note...I'm still waiting to hear from more than just one person that has run a drop-in panel filter while on Cobb's OTS stage 1 map. I don't know how to look at MAF readings and AFR to determine if I'm running too lean. That's where the live data during everyday driving will come into play.
Cliffnotes version: Buy the AP already and try to keep from smiling.
-Jason