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.
“What you've done is done. You've got a goal you never reach, and it's always farther away. It keeps you walking. I don't want to sit down.”