I've never thought so.

Having said that, it's been years since I've watched anything he was in, and I'm a lot more critical and judgmental of performances in recent years than I used to be decades ago. Therefore, if viewing an old Roddy McDowall performance now, I might think, indeed, that he was hammy. However, that's not how I (in recollection from viewings of like the late 1960s through 1990s) remember him being.

Agree. Roddy comes across as well-versed, well-rehearsed and very erudite in his roles and interviews alike.

However, some of his characters (like Bookworms, Academics, Politicians, Authors) are written to act somewhat condescending and rather hammy.

But Roddy's so good at his portrayals that perhaps one may see how some audience members may take one for another and try to connect the dots a bit differently than those who understand that Roddy's playing a role as its author or director intends.

And he certainly has enough acting range and acting experience to get how his characters are supposed to come across, right?

I've liked him ever since his childhood movies. He seemed to have a kind, sensitive disposition.

Right

R McDowall - a well-liked, well-mannered, well-cultivated star from childhood and throughout.

@genplant29 said:

a kind, sensitive disposition.

Because of this, R McDowall is said to be one of the few friends to other Hollywood stars. Not very often you hear that about most others.