I don't think I've ever seen it "look good." Its never been a believable recreation to me. Everyone I've ever met who said "I didn't even notice" is also someone who watched in 3D, and it's totally possible it could blend in with the unfocused and color-muted mess that is 3d. I watch in 2d, digital, and when available in IMAX. And its just impossible for me to miss CGI in digital 2d. But its not the uncanny cartoon faces that bother me, its the inhuman proportions. The animators are just too proud of their "nearly" lifelike work that they don't pay attention to actual human proportions. Every one seems to have a head way too large for the body its attached to. Tarkin in particular was like a watermelon on a toothpick.
And I completely disagree with the idea that Tarkin was "needed" in Rogue One and that fans would have been whining "where's Tarkin" if they had left him out. Peter Cushing is freaking dead, the fans know that and only the stupid, most childish would have complained. And screw them. If you really need to explain it have some background character mention late in the film that "the grand moff" is coming to assume command and you explain away his absence in one line without showing him or even speaking his name.
None of the CGI shots were necessary. And they looked awful. Red leader was almost acceptable, in the effects cockpit with a helmet on... it almost didn't look too bad. But that could have been any pilot and fans wouldn't have cared. They had already teased the Tantive IV with the Captain Antilles announcement and the Vader chase scene, so the Leia scene was unnecessary.
It was easily the worst thing about an otherwise fun movie. It was almost screaming that at some point after a test viewing, some brainless "supervisor" was saying "put more Star Wars stuff in it, people won't know its Star Wars otherwise." A: totally underestimating the average moviegoer (I hate it when movies talk down the audience so "everyone gets it"... if someone doesn't "get it" I don't care, leave that person behind and get on with the story.) And B: didn't realize that this movie was at its best when it wasn't being Star Wars. They were seeing if they could make a different kind of movie within the Star Wars Universe. What it didn't need was more "Star Wars stuff." It quite badly needed less.