I just saw this yesterday after being cajoled into it by my wife. I had very low expectations, and was pleasantly surprised at how misplaced they were. It was a lot more compelling than the rehashed installment from last year.
IMO, it was not only the worst Star Wars movie so far, but one of the worst blockbuster movies ever made.
I fall into the first category. I wanted to see the story of the plans getting into the rebel's hands, and got what I wanted. In addition, they created some fun one-off characters, wrapped up some plot holes in "A New Hope", and threw in some nice nostalgia with the X-Wing pilots.
In short, I wanted another stand-alone episode of the Star Wars space opera, and got it.
I'm hoping there's a directors cut that fixes some of the pacing and adds some more reason to care about Saw Gerrera, but even without I quite enjoyed it – the second time around. I can definitely see how it's very confusing though, for someone not very well versed in the Star Wars saga, or if it's their first movie in the series.
I recommend, if you're a fan of the series, that you see Rogue One again. It did the trick for me anyway, maybe it will for you too.
One thing that did disappoint me quite a lot is the musical score. It feels entirely different from the established themes, and not in a good way.
While it has its flaws, the modern mini series (Game of Thrones, Daredevil) tell much better stories that are more compelling and have depth. (except The Walking Dead, they have some issues)
I would rather see a 6 hour series on Netflix that tells the Rogue One story than a single 2 hour flick with characters that I have no interest in.
But calling it one of the worst blockbuster movies ever made.. can't tell if you're joking.
* spoilers * I found myself caring more for the characters in Rogue One than in most Star Wars movies. I suspect it's because they were (relatively speaking) normal people who could die at any moment, not unstoppable heroes of destiny. They were also deeply flawed and conflicted in realistic and relatable ways. This gave their risks and sacrifices far more gravity, and is why so many people found the final half hour so fresh and compelling.