The evidence supports the fact that he was kind enough. I wouldn't say that it supports him liking it. 2.5 out of 5 stars doesn't seem like "like," to me. Call it what you will, though.
Edit: Actually, from his website it's a 4 star rating. Still, it's not really "like" to me. He basically rated it as "average" for what it was.
Getting back to the OP. I agree that Khan didn't make a whole lot of sense here, at least in my view. The way that whole thing played out was interesting. I think if they wanted the reveal of "Khan" to have more of an impact, or an impact at all really, with general audiences, then I think they should have built up the "idea" of Khan in this film and for this film. That way, when Cumberbatch says he's Khan it has more of a punch. The info we get later on about him from Spock Prime doesn't really do much other than make Spock Prime look like someone who can't keep a oath.
Still, I'd prefer that he had just been Harrison the whole way through.