Ask anyone that runs a storage place. They'll tell you that the units are 99% filled with worthless junk
A friend of mine runs one. They have auctions from time to time, and he invited us out to one. Two things really stood out to me:
1) AWESOME people watching experience. <---actually, this is an understatement
2) There is no good shite in those units
I found out the reason behind #2 later on. When the units are abandoned for a while, the management (and their friends) generally gets first dibs on the stuff. So anything left in the units for auction is what other people didn't want in the first place.