[mlambrecht82]

Yeah, when you lower the compression you are allowing for more boost. The boost is more efficent than the piston having to suck the air in. There is a formula for figuring the actual compression of an engine with boost, for example, say I'm 9:1 stock and running 12 lbs of boost, my actual compression may be somewhere around 18:1, but my car would run better than a car that actually has NA 18:1 compression because my blower is more efficent than a NA engine. So by lowering my compression and raising my boost my actual compression will stay near the same, but I will have better performance because it is a more efficent compression.
I would trust chips burned from Steeda or SHM more than a Diablo Sport. Because Steeda and SHM have their own line of supercharged GT Mustangs with almost the exact same set up as me, where as Diablo is more of a Generic brand that deals with all sorts of makes and models, wich makes it impossible to be as accurate as Steeda or SHM. But believe it or not, every identical car is different, and a dyno tune is the only way to be 100% sure you have the best tune.