They are big. But they're comfortable. Backs and armrests are great, and the heater plugs into a portable powerbank via USB-C. They're great for girls' games and boys' sub-varsity games — there's usually a ton of seating at those.

EDIT: The only time I've used the chair in conditions so cold I wanted the heater to work, I don't think the portable powerbank was really enough juice to make the heater make a meaningful difference. So I'm not sure its worth the upcharge for the heated version. But my wife thinks it is.