After watching the newest episode last night, I have to say it was pretty enjoyable. My main problem is that (SPOILER) there was no real sense of dread or anything for Matt Smith's impending doom. We knew this was his last episode and that Peter Capaldi was next. We never got the feeling that this could possibly be the end. I honestly wish we could have had that suspense of "is this the end? What could be next for Doctor Who?"
Also, I have issues with how the Doctor got new regenerations. For one, it does bother me that Clara has essentially become that "big red button" that can be pressed and all the problems presented to the Doctor are magically fixed. Moreso, I just wish we didn't get the idea that he was given a new cycle of regenerations. I wish we could have had an explanation such as he survives due to River giving up her regenerations, but that he wouldn't really know how much longer he has left. I think it would be interesting to have a Doctor who is actively facing his mortality like what we got a glimpse of with Matt Smith with this episode.