I agree. I'd probably give it a 7/10 or something close to that. The first half was just too slow and not that interesting. I like Donnie Yen in Chinese-language movies, but I just can't stand hearing him speak English. It just takes me out every time I hear him! The biggest problem is that the movie tried to push us to like so many new characters at once, but it just didn't do that great of a job. Most of the characters just weren't that interesting, or they didn't do a great job in displaying their flaws. Cassian (or whatever his name is) reminds me a lot of Locke from Final Fantasy VI. He's the sort of rogue-ish character that's somewhat tormented by his past. The problem is that his "turning point" is really just him saying, "Yeah, I've done some bad things... so I'mma help you!" K4-SO was arguably the most interesting character, because he's the one that actually had a personality. Cassian was the quiet brooding one, Jyn was the quiet brooding one, and the rest.... eh, they were kinda better.
Honestly, it was the end of the movie that showed me why this movie just can't live up to a REAL Star Wars movie. The scene with Vader on the ship was the best fucking scene in the movie hands down. It was a bit short (maybe 1-2 minutes), but it was shot in an interesting, almost horror-like manner that just worked really well for him. It made me realize, "Yeah... I would've rather seen him for two hours than the rest of this...."