I have great respect for Logan Ramsey as Claudius in Bread and Circuses. I felt he had a somewhat bigger presence as a guest star than many of the other fine actors we saw over the course of TOS. I'm glad they didn't try and pull one over us, having him appear somewhere again as another character in the 3rd season. His impact (to me) as Claudius would have made such an appearance all the less believable.
We got to see some of his comedic range in 'The Incubator'......an excellent early MASH episode
I think Claudius is enhanced by the fact that he "gets away with it". Most shows wouldn't leave the antagonist* alive and in charge at the end.
*Even if he does have the whole "I have the utmost respect for you Kirk" thing going.