If I raced more, and had the $$, I'd definitely go enclosed, with some kind of ability to sleep and eat. Hotels and restaurants are a pain. As others have mentioned, you can carry spares, tools and it provides shelter for people and the cart. Don't have to unload/load constantly. I won't even go to a hotel with my open trailer. It screams, "STEAL ME"!
@Demonx2 I wish I had indoor storage for my trailer. It kills me just sitting there a majority of the time. I'm jealous!