I was like "Oh yay" when it happened, but I did also feel that the entire bit was set-up for that specific moment. I think the reason "Blink" worked so well was because everything happened naturally and felt like a brilliant piece of improvisaton. As in, the angels trapped themselves because each was handling the TARDIS from one side, and, with the TARDIS being a rectangular prism, they ended up facing and thus trapping each other. Whereas in this episode they very specifically introduce
teleportation to get Amy out of that predicament
Well, maybe "cop out" isn't the right word, as it did
feel deserved. It definitely strengthened the credibility of River Song as someone you could rely on, if not entirely trust. But in this case, the way they escaped that particular situation didn't feel natural. It's still a very good episode. I'd give it a 4-5 stars.