They all do about the same thing. I like my Diablosport because when there are software updates and more options become available, you can download the updates for free on your PC, then copy them to the programmer.
The unit will store the stock set up so that you can uninstall the madified program and reinstall the stock set-up anytime that you want to. These units lock to a vin# so that your stock program is stored and the unit can only be used to modify the tune on your truck until you restore the stock tune to your truck.
It also can check OBD-II codes and reset them on about any 96 and newer vehicle as well as read and log live data so that actual conditions can be monitored in real time.