I love it.
Yes it was a bit of a mess, I expected a more concise story, especially after the excellence that was 'The Day of the Doctor." Also I was a bit disappointed that Matt spent most of the episode in old age make up, one of the qualities of his Doctor that I liked was his zaniness, and that was lost when he became old. Off the cuff thought but were they making him intentionally look like Hartnell near the end? And also near the beginning when Clara was naked but not really because she had the holographic clothes on...was anyone else picturing Jenna naked during that sequence? Call me a pervert all you like but I had trouble focusing for that scene because I kept imagining how Clara would look if the projection wasn't working.
I noticed a lot of people are wondering why the Doctor decided to stay on Trenzalore and protect it, especially when that felt out of character. Well the way I see it (and this is just an interpretation, feel free to ignore it) is that he fully believed that planet was where he was going to die. Also knowing that he was out of regenerations I suppose he felt like he was doing the proper thing by allowing himself to die on Trenzalore, also perhaps he felt it was a fixed point in time so it needed to be done. Regardless this is one aspect of the episode I had no problem with. Matt's final goodbye was great and it did break the fourth wall I thought, not in a bad way though. I also liked seeing Karen again and since I had no idea it was coming it was a nice surprise
And I can't leave out Capaldi. I think some people are saying they can't see him as the Doctor because well....they really haven't seen him as the Doctor. It's just like when Daniel Craig was first cast as James Bond, I certainly couldn't picture him as the character because he hadn't played the character yet, same for Capaldi, kind of. Regardless I can't wait to see his first official story and his line: "Just one question: do you happen to know how to fly this thing...?" was probably the best line from this episode. Certainly my favorite.