I bought it! Not as Peter Cushing, but as the character of Tarkin.
I actually had the opposite impression; i think CGI was a very good technique applied to a somewhat rigidly written character that is not the Tarkin I remember from Star Wars but a cartoon full of prejudice, that carries himself around playing the cool and sophisticated “typical” british that never gets angry or shows emotion under any circumstance.
It felt like admiral Tarkin from the clone wars cartoon.
In SW 77:
Where is the rebel base? - Sounds and acts physically intimidating
Vader, release him! - Sounds and acts angry, commanding yet slightly frightened
Evacuate? Now, In a our moment of triumph? - Sounds and acts anxious, a little shouting and with a higher pitch
The Imperial Senate will no longer… - Sounds and acts bored and anxious, knowing that conversation wouldn’t get anywhere given the news he is carrying.
In RO, we got a guy with Cushing’s face that doesn’t cast much emotions other than staring at people with a cold gesture. In fact:
Speaks about the Death Star aboard the Star Destroyer - Stays cool staring at the void and speaks with a non-inflectioned voice
I owe you an apology director - Stays cool staring at the void, then turns around and evil face.
Is informed of the plans of the Death Star being in danger in Scarif - Stays cool staring at the void and utters some command as if everything were under control (the same high stakes that got Vader to a level of brutality that we haven’t ever seen)-