I wouldn't say one is easier or more difficult, but when you're inside a costume and a mask, you have to endure heat - and, often, difficulty seeing. The vision is not very good in a mask. And you have to cope with that, as well as trying to think about this character.
“In front of us was not a line but a fortress position, twenty miles deep, entrenched and fortified, defended by masses of machine-gun posts and thousands of guns in a wide arc. No chance for cavalry!”
“I don't want to think about how many people have thought or still think that I'm crazy.”