I didn't really mind the CGI work with Tarkin, but the Leia shot at the end was really jarring. I don't know if it's me, or if we've placed too much criticism on CGI performance. I don't think with the way our minds are hard-wired, that we can ever be fully convinced that a computer replicated face can pass as the real thing. Something in our minds won't allow that to register, and that's where I think part of the problem lies.
If they ended up recasting the role, I think there would be less controversy, even if the actor didn't look one hundred percent like Cushing.
I wonder what kids will think about CGI Leia in 20 years. I spoke to a co-worker today who came of age during the prequels and admitted to liking them as much as the originals. I was absolutely floored by his statement, and wondered what he might think of CGI Cushing, as opposed to Peter Cushing. Will he have the same discerning eye as those who notice these types of discrepancies? Not that it bothers me, of course, but was thinking about that when I was walking out of the theater last night.