I have had a 55 # in the past and loved it! Only issue I had was that it would get hot and melt a wire on the inside of the top. It was a 12 volt system, don't know if you can still find them in 12 volt but imagine you can and mine was years ago so I'm sure they have addressed the issue I had in mine. If I was to buy one today, I would go with a 55!