the AP builtin maps are okay, but they certainly aren't going to be as good as a protune. You can get a protune with an AP, in fact many tuning houses prefer them. It's really your choice; if you like the looks of the opensource tools and can use your laptop in your car, I'd say go for it - you won't get those "stage 2" maps (well, unless you ask some of the people who make free maps), but you'll get a lot more insight with the datalogging, easier tuning if you want to do it yourself (it's really tough, but at least you have access to the maps - for better or worse), and a well-respected medium for tuning by the experts.
If you want easy, go cobb. If you want cheap and extensive, go opensource.