Here's one on a 07+ 350Z. Gives you an idea. They are the same thing. Just imagine taking your car to Shop A vs. Shop B. They're doing the same thing, two different people are mapping the car. But remember that there is never a replacement for having YOUR car on the dyno. Mail order tunes won't have the same result as the dyno below. Any responsible engine tuner will de-tune the map for safetey.
However there are plenty of hacks out there that send the maps out tuned right to the edge for partiuclar car that was in the shop that day. Then things can go boom.
