Giving it four out of five (which is my "excellent", basically).
Some lovely moments, such as the one where Lambert and Hussein hug each other after the ratings are released. Reece Shearsmith's Doctor Two was spot on, also (though how accurate that was to Troughton himself, I'm not sure).
The bit at the end took me out of it somewhat. I wonder if we'll be seeing that scene in a different context before the end of the year.