I think it does let you go in and play with the tables if you want. I strongly recommend against it unless you REALLY know what you're doing and I can guarantee you I don't. I played with mine a little but afraid to go down that road in fear of doing damage for my ignorance in that field.
Mine worked pretty good on their tune with what I have. I did the autotune and applied that to their tune, but didn't really notice any night/day difference. You have to run the autotune long enough to fully populate all the tables, they say it will be shaped like a football when you are there or close to it. It's pretty hard to fully populate every single rpm and speed and throttle position.
The only two changes I made were setting my throttle to full race (very responsive) and I changed the idle speed a little when it gets to a certain temp. just so I would know it's getting pretty hot without pulling my phone out to actually see the temp. All in all I love mine and no problems as of yet.