I bought BGEE, BG2EE and PST earlier this week for the iPad. I have some trepidation as I never expected them to be as good as the PC versions, but they are, because they are a slightly different experience.
The hint buttons to highlight important items/people are really useful and unlike the PC version can stay on all the time.
The BG games are still on version 1.3 rather than 2, which I find a good thing in some ways (as 2 still has a few teething issues IMHO).
The interface buttons behave differently, making it harder to play with pausing, which is actually quite refreshing.
If you don't like version 1.3 then there may be a problem.
Unlike the PC versions, the additional portraits/soundsets and the NPCs Hexxat, Dorn and Neera are only available as additional purchases (booooo). But then again it allows me to concentrate on the core characters, which I like, and I think you do get Rasaad for free, and that's nice. As a result I probably won't buy the add-ons because I don't feel I need to.
No SoD I don't think (as there's no version 2).
I can't see how you can mod or use cheat codes in these apps.
All in all I'm really enjoying them at the moment
Well done Overhaul for introducing these versions
PS At the time of writing, IWDEE, BGEE, and BG2EE have been removed from the AppStore where I am - is this permanent? I hope they come back, because then I'll buy IWDEE too