Living on the lake I never had a grill last more than 3 yrs. Moisture kills burners and anything not made of stainless steel. It's amazing how much faster stuff rusts sitting 10' from a permanent water source. I think my cover hindered more than it helped. I have a stainless grill that had some non stainless mixed in here and there and that stuff has all rusted away leaving me with a SS shell.
I'll be picking up another grill this spring so keep the feedback coming.