I actually like the more 'sparse' series arc. I think I'd enjoy something more elaborate for next time, but this was nice enough after all the Cracks in Time and Silence business. The great thing is that every season with the Eleventh Doctor connects in some way, so all of it has some sort of über-arc: the cracks in time lead to the Silence, the Silence led to the background arc early this season (which was set up at the end of the last one) of the Doctor deleting his trace on the universe, and the mid-season arc of how he ends up on Trenzelore, which has a lot to do with the cracks in time, the Silence and his identity. I think it all connects pretty well.
About the series finale episode itself, as an episode it was really good. As a season finale, meh, but as I said, you can't really pull anything more complex out of your ass if you really haven't established a complex arc for the series. It was more about the Doctor himself; yes, there was the mystery of Clara, but that was in the background.
The really great thing for me was the last two minutes of the episode, really. They could've happened in any other context. They could've ended up there in many more interesting ways. But once the episode is done, I'm not thinking about the underwhelming villain or really short 2nd act (there's very little action in this episode, which is very weird for a Doctor Who finale.) All I'm left thinking is... "OH MY FUCKING GOD. John Hurt... as a previously unrevealed incarnation of The Doctor!"
I think that was pretty interesting. He's there for just seconds, but the short dialogue exchange reveals a lot about the situation. First, he isn't really the Doctor, because he did something so horrible that he doesn't live up to the name. Matt Smith's Eleventh Doctor recognizes this incarnation, so it has to be in his past. We know that the "First Doctor" hadn't still regenerated, and we have seen every regeneration but one. So there's only one single possibility: John Hurt's incarnation is a previously unknown incarnation just after McGann's Eight Doctor, but before Eccleston's Ninth Doctor.
The few lines they exchange hints at this too. The 2005 reboot started with Eccleston's Doctor just after an unseen Time War between the Time Lords and the Daleks; we don't know much, but we know that to end the war the Doctor had to kill both the Daleks and the Time Lords. He committed two genocides. So, I'd bet that these atrocities were committed by John Hurt's incarnation, breaking the promise that the "Doctor" moniker entailed. He's the real Ninth Incarnation, but not the Ninth Doctor, because he didn't live up to the name. When John Hurt's Doctor defends himself by saying that he did "what he did" in the name of "sanity and peace", Smith's Eleventh Doctor sums it up perfectly: "You didn't do it in the name of the Doctor." That "it", I'd bet, is the destruction of two species to end a war.
And, about the "Name of the Doctor" twist, I think it's great. If it was a common or invented name, what of it? It's just sounds. It could be "John." Or "Galafeiskkor" or something even more random. It was obviously going to be something else, something symbolic and meaningful. But it'd be cheesy if it was something generic, so it was what it had to be: "The Doctor" may not be a real name, but it is the only thing that matters. As Smith's Doctor says, he does what he does "in the name of the Doctor" —and not only is that the real meaning of the episode title, it also is the only significant meaning his name could ever had: his chosen name is what matters, because it symbolizes the promise he made to help people.
In that sense, it was a wonderful end —it might not have wrapped up a previously set up complex mythology like many past series, but it did wrap up the Doctor's emotional journey through the season, and it sets up the future just perfectly —it is, indeed, a great opening to the 50th Anniversary Special episode. It's not much of a spoiler, as BBC told it to whoever would listen, but —SPOILER— Tennant's Tenth Doctor is coming back for November's 50th Anniversary Special. Tenant's and Smith's Doctor teaming up against (or with?) John Hurt's Doctor is going to be spectacular.