Just saw it last night and here are my initial thoughts:
1) A DEFINITE upgrade over the 3 previous installments; this movie FELT like a SW movie and sounded like a SW movie and, perhaps unfortunately, seemed to directly borrow plot from all the 3 original movies.
2) I thought the acting from the 3 main newcomers was excellent with particular strength coming from whoever the dude who is playing FIN. He was really good during the comedic scenes and seemed to play the part of an unwilling hero quite convincingly.
3) The two older characters probably shouldn't have been inserted in there IMO. Harrison Ford was aight at times, but Leia's insertion was a misstep.
4) I actually likes the casting of Kilo-Ren (sp?)....I like he isn't handsome or dashing, I like that he looks a bit EMO and I like the very predictable apex of the movie bc it allows us the viewers to hate him as deeply as Vader before his rehabilitation. He had his opportunity at redemption ala Vader and he chose quite clearly to side with the Dark side....
5) I wish they had cut one or two fight/action sequences and developed some of the relationships a bit more. Why is FIN and the X wing pilot (?) hugging at the end....because they knew each other for 14 mins once? Why is Carrie Fisher stroking the female leads face at the end? They didn't develop that at all.....
6) John Williams, wow, just wow. What a talent we have in John Williams.....guy just can't miss...pure genius.
Those are my thoughts, but overall it was a worthy effort assuming things go up from here.
Oh, and I was disappointed to hear Abrams isn't signed for the next movie; he did an amazing job imho directing. Writing, meh....maybe not so much.