One of the main reasons we moved to where we are now is so we can have our camper at home with us. It's so convenient to have it there. Like our first trip isn't for a month but we can just go out there this weekend to get the entire thing cleaned and ready to go, since we are busy every weekend after this until our trip. Also, we have to take it to the dealer to have a few things done to it before the trip, so having it right outside saves about an hour of time since we don't have to drive over to the storage place first.
The only negative of having it at home is it's sitting outside in a very wide open space. The sun has really done a number on the sides that face west and south. We're spending a lot of money to get it looking nice again. We're also getting ready to build an outbuilding to put it in.
But prior this house we had to use a storage facility since our old HOA didn't allow campers to be outside. For us, the important things were security and how easy it was to get the trailer in/out of the space (like was there enough room to swing out to back it in straight etc.
The facility we ended up using had on-site managers, they lived in a house right next to the front gates. They were former full time RV-ers and at the time, we were new camper owners so they were helpful when we had questions... really nice people. Each "tenant" had their own code to get in and out of the gate and there were cameras. Also the facility was also used by trucking companies to store extra trailers etc. so they had nice wide aisles that were easy to get in and out of. They also had 12' high fencing around the entire thing. And, sounds silly, but they had a large population of feral cats running around which helped keep mice away from the trailers.