Open-back headphones let in outside noise, closed-back headphones isolate you from outside noise.
Open-back headphones leak sound to the outside, closed-back don't.
Open-back headphones tend to have less bass than closed-back:
Open-back headphones are usually less sweaty than closed-back.
IMO, if your environment is quiet enough to where open-back headphones are viable, then I would choose open-back.
Closed-back only if you need the isolation.
But that's subjective.