They made one of the best Fallout games imo, Fallout:New Vegas....but, they are not a particularly great studio. Certainly wouldn't be top of my list of studios to buy. But Pillars of Eternity is well praised on PC.
I just hope MS has positive affects on these studios they are buying, cause they aren't really top tier devs. Everybody going gaga over Ninja Theory cause Hellblade is decent...but the majority of their games are pretty mediocre.
One of those things where we just have to wait and see, I guess....one thing is for sure, these studious need to come out strong or MS is in for a world of negativity again. Not just quality either, but creatively too. If Ninja Theory is the only one doing a new IP then MS are gunna be in for it.