I am not sure I would call it sloppy but rather "flexible" as the trailer is moving and bending. If it was too rigid, you would risk cracking. Heat and cold are a factor as well as I notice it shrinks and contracts somewhat.
I also know what you mean about the running on the floor....frustrated me as first, but now I just make sure I level the trailer in such a way the tub is pointed slightly backwards - has not been a problem since. In the rare occasion I have not gotten it quite right, a wash cloth lying on the edge takes care of it. I just don't like the way it looks having a caulk dam there....but I am kinda picky