The apocalyptic future worked well - vaguely matrix-like, with lots of Sentinels killing mutants - and anyone who carries the x-gene or its precursers, sympathisers, and anything else the ruling elite don't like. It's a nice touch that we never see this elite, only their Sentinel minions.
Back in the seventies there's a fairly realistic portrayal of Richard Nixon which manages to stop short of parody, and a nice frothing performance by Peter Dinklage (Tyrion Lannister etc.) as Bolivar Trask, the main villain, who seems to be the Anti-Stark.
The ending is ambiguous enough that it's not clear if they're restoring the original X-men timeline or making changes - one change is obvious, but is a spoiler, something else at the end may make big changes to Logan and his back-story.
The end credits scene is right at the end after all credits and is annoyingly cryptic for those who aren't very familiar with this universe, someone making serious use of telekinesis. No doubt there'll be plenty of explanations available soon.
Overall I liked it a lot, and will probably get the DVD eventually.
One thing - if Stan Lee was in it I missed him completely, a first for Marvel movies. Anyone know?