Thats what I thought too, I have alaways stored it full but two winters ago I left it 3/4 and had nothing but water in the tank in the spring. I have seen the outside of the tank sweat like crazy when I was installing it over the course of a couple of days.Upper 20's at night high fortys in the day I'm talking hot cold over the winter, I can't expalain other wise how I have never had any water in there and when I left it not full I had lots. I had so much infact that it got pulled right throught the racor and my Suzuki primary filter had a half inch of water in it too. Good thing I stopped to check it after running it for a little. I thought it was bunk to until the old Blazer I had stopped running one day and I talked to the old owner he siad did you drain the water out of the tank? I said waht? Thats what I put screw in the bottom for. This old Blazer would sit around with a 30 something gallon tank and make water like crazy. Sitting for two months you pulled the screw out of the bottom of the tank and you would get a half a bucket of water out of it before any gas came out. I did this many times belive it or not. Maybe empty is better than half I dont know all I know is the only time I have had trouble is when it wasn't topped off. Heck the origional gasket lasted twenty seven years before it gave up, it even looked like it was a piece of a rain coat cut out and put under the sender. Maybe thats what I should try
