I liked it quite a lot. I think the first hour is pretty great - Ridley in particular does a good job.
The middle section is a little muddled, although after just one viewing I can't pinpoint exactly why.
And then the 3rd act is the most problematic, primarily because of the Starkiller Base.
Almost immediately after leaving the cinema I started considering ways to fan edit some of the issues I had out of the movie. Mainly:
1) There were too many fan service callbacks. The three I'd cut: Finn and the chessboard, the 14 parsecs bit and the trash compactor bit.
2) The smuggler and tentactle monster scene. It may be impossible to cut the whole scene as otherwise presumably Rey would just have gone straight back to Jakku, but something about that whole scene was off. I can't explain it in more detail after just seeing the movie once, but it didn't work for me at all.
3) The last shot: surely it should have been on Luke's face not on the swirling around wide shot?
4) And this is the big one, and something I'm not sure is possible. I'd love to get rid of the Starkiller Base plotline altogether.
I'll go into more detail about this one...
I'd heard the criticism over and over again before seeing the film that it was basically just a remake of ANH, but I didn't feel that way until the 3rd act. It's really only with the Starkiller Base that it becomes too familiar. Plus, that whole storyline felt like they were going through the motions, giving us a new Death Star out of some contractual obligation with the fans. It's hardly mentioned until it destroys that system, and the final big battle didn't grab me at all. It was unexciting, predictable and dragged down the last act.
So I'd propose having Ren kidnap Rey and take her to the base, which is some unnamed First Order base on that world. Then you have Han and co come to rescue her, you have the lightsaber battle, Han and Chewie set the detonators and blow it up from the inside.
I'll repeat that I've only seen the movie once so it's entirely possible there is some structural reason you need the Starkiller Base and the whole Death Star Redux element to the movie. But the only one I can think of, is if that system destroyed is Coruscant. If so... well, that's the end of that idea. But if it's some other, relatively insignificant system to the wider trilogy story then I hope we could cut it all.
It would make the final battle much smaller and more personal, more akin to TESB than ANH - but for most of the runtime it felt quite small and personal anyway, and the whole Starkiller thing was shoehorned in pretty gracelessly to give them the big bombastic ending that didn't feel earned or even necessary.
I'm slightly hungover today so hopefully that all made sense.