I watched it for the second time this weekend. My previous experience being the opening weekend at the Leicester Square Laser Projected 3D IMAX, so it's been 18 months since I saw it.
It held up for me, though I would argue that it's not really let down by a bland lead actor - more that the entire cast weren't really fleshed out in any way. That's not necessarily a criticism, as movies with very little back story about characters do work (see: Dunkirk). It's actually the links to the original which take me out of the movie. When Grand Moff Tarkin first appears, I didn't even catch his first lines of dialogue as I was too busy inspecting the CGI. Also the shoe-horned in footage of Red/Gold Leaders from the original Star Wars - It makes sense they would be the squadron leaders but it just blips me out of what's happening because your brain goes "Oooooh it's that guy, they must have used outtakes"
The locations (Jedha, Vaders castle thing on Mustafar and the end on Scariff) felt more distinct than Solo though and the cinematography was better on Rogue one.