Really, the two main things that bother me about Seasons 5+ are that I never quite got used to Matt Smith (I still don't think he plays a proper Timelord. He lacks Grandness. He doesn't have the fury. He isn't the Oncoming Storm, he's a child.) The second is that the energy seems to be missing. I don't get excited and caught up anymore. I could tolerate much more silliness if it was entertaining.
Not sure why I'm spoilering this, but why not? Grandness isn't a guarentee in a timelord. It's not even a guarantee in the Doctor. I mean, consider Patrick Troughton, Peter Davidson or Silvester McCoy.