It's so nice to see our oldest members return.
I was really excited to see the 1st doctor meet than 11th, but was really disappointed at the weak story. It was really nothing more than a longer version of the "I don't want to die" ending that we had with the 10th (Tennant). But less interesting.
The return of Bill was shoehorned in, zero point to it. (I was wholly disappoint by her "happy ending" demise at the end of Series 10, instead of simply showing how the doctor's companions don't always get a happy ending. In fact, most don't, especially due to Moffat's writing.)
I'll accept a female doctor as soon as little girls accept hairy overweight men being Disney princesses. I'm not opposed to, for example, Sherlock Holmes sidesick John Watson becoming the Asian female Joan Watson on Elementary. But you don't make Sherlock a black gay man, or a woman, or something. Go make a new character, don't screw up the one we already have!