I checked into this a while back and passed for a couple of reasons. 1) Your RV is packed into a warehouse and not readily accessible. You can only access it when their warehouse office is open. Also they were very evasive about insurance coverage in the event of damage while in storage, especially since they are the one's doing the parking of your RV and they keep the keys while it's in their warehouse. That was a deal breaker for me.
2) The cost estimate I got then was $10 per foot of length per month. That would have been $400 per month !!