Large fractional operations. We do not wear uniforms in the sim. Some pilots do, but that is their own choice. Our American branch of the company do not wear uniforms. Note, there is a dress standard which we're expected to maintain. I too, prefer my work shoes for the sim, same reasons as given above.
Many of us travel to the US for our sim training so carrying the uniform as well as civvy clothes is a pain. (Our training usually lasts 4-5 days).
Our time slots are interesting and so being able to head out of the sim and go to a restaurant for lunch is great.