I've had my chest freezer fermentation chamber in use for a little over 7 years, and there are only a few rust spots on the interior. They don't affect anything, and I'm sure I could mitigate them if I felt the need.
The air is pretty dry out here in Los Angeles though; maybe it's more of an issue if you live in a humid climate.
The only thing that's kind of a pain is lifting fermentors in and out, but I'm relatively young and in good shape so it hasn't been a problem. I also ferment in stainless vessels. I would definitely not try to lift glass carboys in and out.