I don't even remember the computer I was using with NWN2 and MoTB but I don't remember any problem at all with performances. Lol perhaps it's the current computer I'm using, I quote there's on it NWN2 and MotB installed and don't remember why they are here. It's weird I never played the other extensions.
EDIT: Now I remember in fact I played NWN2 on Mac and MotB on PC and weird it's possible it was with the current computer I'm still using. It seems like an eternity in the past.