I have mixed feelings as well. It took most of his first season to warm to him. I feel like both he and the writers were unsure of just who the Twelfth Doctor was, and the conflicting visions didn't help the matter much. With Matt and David, we pretty much had a feel for them by the end of their debut episodes. I straight up disliked Capaldi's Doctor until around the three or four episodes in. But by the season finale, they finally found just the right mix of elements that endeared him to me, and ran with it up through this last pair of Christmas episodes. I've come to like him a lot, but I don't think I'll miss him the way I missed his recent predecessors. I'm sure the regeneration episode's going to sting, of course.
As for Moffat - mixed feelings. I'd say his overall run as showrunner was superior to RTD's, but there were some serious pitfalls along the way. He wrote some of my favorite episodes of the modern series, but some of the stuff made under his supervision in recent years were pretty bad. Things kind of bottomed out after Time of The Doctor. There were a lot more dud episodes in the last two seasons than there had been since the early growing pains of the series relaunch. Last season's arc was really weak - and Ashildir was an unbearable character. We got told some interesting things about her, but witnessing her in action was no fun for me. This year's season of Sherlock was also a big letdown in the writing department. I think he's probably just burning out - he's had some great ideas, but we can't expect them constantly. That said, I'm cautiously optimistic that a fresh showrunner and a new Doctor will lead to great things.