I'll miss him lots. Technically, Sylv was my doctor, but David Tennant, well, I wish he had been. I don't mind admitting that I had tears in my eyes the moment I heard those four knocks, and it was a real gut-wrencher right to the bitter end.
A more than decent legacy, with particular highlights being Silence in the Library, Blink, Family of Blood, The Satan Pit, and The Girl in the Fireplace (a bit of a grower in my case, I'll admit) By no means perfect of course, but this is not the time to dwell on the Shakespeare Code, Fear Her, Voyage of the Damned or some of the more atrocious endings (Last of the Time Lords, you know who you are).
The way I see it, and I realise this is very much the orthodoxy, but so it goes, Rusty does some things very well - imaginative premises, multiple plot strands, sudden twists, and some great dialogue - the scene between Wilf and the Doctor in the cafe in part one of End of Time is a classic. His flaws for me are the hand-waving deus ex machina devices, the ludicrous technobabble and what sometimes seemed to be an over-easy lapse into saccharine resolutions despite dialogue protestations to the contrary. Still, end of an era stuff this. Luckily, the Doctor always provides a handy visual metaphor for change and rebirth at these moments.
You can probably tell from my list of highlights that I'm very much looking forward to Stephen Moffat's reign. Like the alien said, allons-y...