I've signed up for this with our season tickets, as a lot of people do. It's super convenient and has the added bonus of keeping people out of your seats.

Every so often, you get the group that stakes out its territory in other people's seats and/or spills over by a seat or two. I'll get people to move if needs be, but I'd rather not mess with it. It'll probably happen eventually, but I've yet to have people move my stadium chairs.