Just saw the premier last night, and, yeah, Mother is pretty amazing. Outside of her, though, I thought the episode was so-so.
Oh it most definitely is a set, over at the Fox lot. My friend and former co-worker David works in post on the show and has shared a few photos every now and again, and if you look really carefully, you can actually see him in the last scene of the finale last year (when we met the mother!)
Here are two photos, one of which very obviously shows that the apartment is definitely a set on a soundstage:
Did you give him an intervention?