Supposed 10 hp increase on 91 octane and 15 on the 93 octane tunes at the moment.
That isn't stellar, but keep in mind, with the tune you can also reset or change the factory transmission settings which makes a massive difference in drivability. You can also raise the redline. You can add more fuel if you're getting some knock. You can make the throttle more responsive or slower. You can turn on and off the multi displacement technology.
And of course the data logging.
Now if you buy the tuner, you can data log, then send data to one of the forum tuners, and they will tweak your map for you and get you more then that 10-15 horsepower that comes with the unit. This is especially useful if you have an intak or exhaust among other things to help the truck optimise the mods.
This only works on the 2012 however, the 2013 computer hasn't been opened up as of yet. As far as I know. I'm not sure which jeep you're running, so all this information could have been useless.
I'd recommend it. I barely noticed the 10-15 horsepower, but I definitely can tell there's a massive difference in the way the transmission is working. I bought the unit in anticipation of an intake and a few other toys. I will get a tune, and it will be a different animal after as a result.