Gillan and Darvill are brilliant as Amy and Rory, but watching season six one can't help but worry a little bit about Smith as the Doctor. The character is, and needs to be, at turns mad as a Hatter, funny, and angry. Smith handles the first two of these very well, but is never quite believable as angry. Even in the scenes where people have angered him to the point where he is ready to destroy everything and everyone in front of him, you still get the impression that he's about to make a joke about suspenders (or bow ties) being cool (and while they may be, the joke would be misplaced at such a moment). There is a necessary, even if it's only momentary, gravitas required of the Doctor (he is, after all, a destroyer of civilizations including his own), but one never quite gets that from Smith's Doctor even in scenes where it's meant to come through.
On the technical side of things, the Blu-ray release is truly excellent. Even if many of the episodes follow the same story, they still are given varied locales, allowing for different looks. The colors are brilliant – rich and beautiful. The amount of detail, too, is impressive, and even in the dark things are visible. Textures are readily apparent and black levels are good as well. In terms of sound design, the set features a 5.1 DTS-HD track and that, too, works. It is well mixed, with dialogue, music, and effects balanced properly and placed appropriately within the sound field. Plus, all the odd little wibbly bits of sound one would expect from alien ships, worlds, and bases are all there, truly putting the viewer square into the middle of the Doctor's battles. In short, while you may find issues with quality of the stories themselves, you won't find any with their on-disc presentation.
In terms of the special features with the set, there are several different "Monster Files" which give a closer look at the various baddies the Doctor faces this season as well as prequels (short little teasers) for several of the episodes. The teasers aren't terribly interesting, but the behind the scenes Monster Files most definitely are. The shorts that are far more compelling are the "Night and the Doctor" ones (five are present) which allow Smith to rant and rave as the Doctor (the man is great with words even if he has trouble with anger) and gives us all a little insight into what goes on in the TARDIS at night. It is actually something of a coherent story (mostly), and a lot of fun. There are also commentary tracks for select episodes and two Comic Relief sketches. The best of the special features are the included episodes of Doctor Who Confidential which are general behind the scenes pieces for specific episodes of the series (they're located under "Episodes" on the final disc in the set… well, they are except for the Confidential on the Christmas special and the one on Night and the Doctor/Comic Relief episodes). It isn't the most involved set of special features ever, but they are enjoyable and informative, particularly the episodes of Confidential.