Film was great fun, and managed to combine old and new very well.
If you like "Star Wars" then you will almost certainly like this, which is very-much "More Star Wars". If you don't, then you won't.
I shall almost certainly go and see it again, so I can experience it without expectations hanging over me.
theweaselking has a good review here, which points out Abrams' usual problems with time/distance (which were one of the major things that pulled me out of it). Worth reading the comments.
theferrett has a review here, looking at the plot in more detail, which I largely agree with.
And between the two of them they cover pretty-much everything I think about the movie. Which is great, because I don't have to actually set my brain to the task of writing a review.
Also, for filling in the missing bits:
What's going on with The Resistance and The First Order.
25 questions from The Force Awakens, and some answers to go with them.
33 questions that IO9 want answered
Personally, having to fill in the blanks of the background politics, history, etc. is one of the things I've never minded, and sometimes enjoyed. One of the things that made Star Wars successful was that it frequently hinted at a larger universe, which made it feel bigger, and more real, than it would otherwise have done. "The Clone Wars" were just a throwaway line in "A New Hope", for instance - flavour that gave fans something to imagine. But if you want to know the relationship between The Republic, The Resistance and The First Order, then off you go :-)
Comments almost certainly will contain spoilers, of course.
Original post on Dreamwidth - there are comments there.