Short form: An enjoyable comedy that was far smarter than I had feared.
Terrance Stamp was, unfortunately, wasted in this movie, but it was largely because they didn't quite set a consistent tone. The comedy oscillated from slapstick to cerebral, and Stamp was caught in the whiplash. (Ditto Bill Murray, but his role was more cameo than anything else.) Thankfully, the rest of the cast was quite at home with this. Alan Arkin was wonderful, as were Dwayne Johnson and Masi Oka, both finding their centers quite readily. Steve Carell slipped into his somewhat usual role well, delivering the appropriate deadpan. Patrick Warburton was wonderfully cast for his walk-on, as well. The plot was iffy, but it's a comedy, after all. All in all, worth it, in my view.
ETA: It's telling that I forgot (in my relative haste) to mention my opinion of Anne Hathaway's performance. She was tolerable but honestly somewhat forgettable, since she was very much the "straight man" most of the time.