Saw it last weekend. It was genuinely a lot of fun; I find myself wondering why the MI movies haven't gone to complete shit when they had every right to following the original three.
Just came back and am still kinda pumped. It was really good, and you do not feel the near two and a half hour running time at all. The action set pieces were superbly shot and directed. It was hard to see much in the way of CGI, which means Tom Cruise was once again putting himself in absurd amounts of danger for our collective amusement. Also, it's a minor thing, but I really like Ethan Hunt as a character, and his utter refusal to be anything but a full blown Paragon, regardless of how much harder (and painful) it makes his fucking life. It's refreshing, honestly.