I rejected this film as soon as I saw it due to it's awful non-canon status, beautifully outlined here:- http://cinekatz.com/2016/12/25/rogue-one-is-not-canon/
However, I will say that from what I remember it was a well enough made modern blockbuster film. What I find weird though is that it seems a lot of fans seem to love this film, e.g. calling it the "Empire" of the Disney series, whilst hating the TLJ for disrespecting the established canon (which I'd also say is true). This I cannot understand.
It can't even be due to treatment of well loved established characters - In Rogue One Darth Vader is shown as a lowbrow thug henchman scything through the common footsoldiers with his lightsaber, yet supposedly it's the same guy we see shortly afterwards in ANH leaving the dirty work to his troops before imperiously marching in afterwards! Surely that's no worse than the character assassination (which, again don't me wrong, I agree that's what it was) that Luke suffered in TLJ?