+1 especially for what xmonie said about being a little scared at first. I am not a newbie to wrenching, but definitely to turbos, all wheel dirve and computer tuning. I was mostly inticed by the price of the Tactrix. There are definitely advantages and features that go along with the higher price tag on the AP, but you get your moneys worth from all accounts I have heard. My buddy has the V1 AP and pretty much were are identical on the mods except EM and in my opinion (since I have driven his car as well) I feel we are neck and neck. In other words for the stage 2 map from XPT, it would be a drivers race. I would highly recommend you read up on all of the software (enginuity, ecuexplorer, ecuflash and on the osecuroms.org forums) just so you get a little more familiar with what`s going on before you commit. Something to consider is wether or not your local tuner can dyno your ride. It is not neccessry at stage 2 , but if you decide to go to higher ponies then it would be a plus. Anyway, I can`t emphasize enough that you will NEED to read until you feel comfortable enough in doing the Tactrix. There are a ton of threads already on this forum so just do a search on Tactrix or Opensource and look over those threads. Also do your homework on AP since you might feel that is a better route for you.
BJJ for the win!