My stepdad and wife were actually truly surprised to find out that Tarkin was a digital creation. (They figured Carrie Fisher was one).
My one real issue with the R1 Tarkin is that he was too expressive. Cushing’s performance in ANH was much more subtle so it therefore no longer felt like the same performance. Were it another actor, it’d be different - a different interpretation if you will. But because his face was realistically recreated, it made all of the grimacing and snarling and raised eyebrows that more off putting.