I'm not aware of Personal Transformer2 at all, so it isn't like my mod is trying to fix/add something missing from Personal Transformer2.
From quick look at it:
- Personal Transformer2 supports everything this mod supports
- Personal Transformer2 has some extra features
- Personal Transformer2 is probably more tested and therefor stable, since I basically written this mod from scratch today
- Balance is totally different in each mod
- I can't speak on performance impact of either mod
So I guess pick one you like more and enjoy