So I have played about 30 hours of the base game and keep meaning to go back...got hooked on the fishing for some weird reason...this may bring me back in.
I never played very far into Underrail, but it seems decent enough. Maybe I'll give it another shot.
I seem to remember a lot of people complaining about the endgame.. something about it being quite frustrating if you didn't have the right character build. Perhaps the additional XP from the expansion will go towards remedying that.