It really is a good question. I imagine I would tell the person thank you, compliment them on how much work it must have taken, accept it with grace and take it home. What I would do with it after that I don't know, probably put it on a shelf someplace and use it for the kids when they spend the night.
My fear in giving quilts is will the person who gets it like it? I would need to know their likes and dislikes well.