I went to see it a few nights ago and mistakenly thought it was part of the new trilogy. I spent the first part of the film wondering why there were so many changes of scenery and new characters and I was convinced that the captured pilot was Poe. Even when I learned it wasn't him I was still expecting the young team from the previous movie to come in at some point and make it tie in. Even after them talking about the Death Star and all the characters being done away with it never actually made sense until about ten minutes after I saw the final scene.
Knowing what I know now, it's an excellent stand alone film and even though the characters are disposable, you connect enough with all of them to make their fate matter to you. Links perfectly with the film it's supposed to.
The rebels aren't half a complex beast now with all their splinter groups and cold blooded killers. The historical references are all part of the fun though.