I know this isn't a straight up comparison,
I took my srt to jerry last year. he had previously tuned the car and tested on his former 2wd dyno..
w a canned tune from eurocharged it was making 330 rwhp, after adding headers/injectors, my reading went to 384 @18psi,on his then, brand new all wheel dyno. the real gains weren't huge, in fact the hp dropped a handful of hp (390+w canned)_. the real gains were in the engine drivability, it was vastly improved. the fuel mileage improved somewhat and oh yeah my tips and bumper cover stay very clean now. it is very smooth at all times. its very smooth and deceptive to the driver. and my afr's are fine.
it runs like a Mercedes, loud, fast, smooth.
as les has stated before, jerry is cautious with your engine and will not smoke it w his tunes. no one has burnt one yet, that I have heard of. and the cost? I have spent more for dinner and received a lot less satisfaction. this is more qualitative vs quantitative. a lot of the effort was in cleaning up mid range vs wot.
the dyno tune was all about smoothing up the rough edges apparent in the canned tune. it took some time, we waited, but its always enjoyable to be at eurocharged, everyone there is friendly and knowledgeable.