Deer Valley Storage is a very good storage facility in Phoenix, Az. We have kept a storage unit there for several years now. They don't raise your rate all the time (never since I've been there}. Definitely a good bargain for storage!
I used some extra storage space that I needed from this place. It is very decently priced, but is good for only the stuff you might as well store in your garage. There are no special storage facility as such, but has quite a variety of sizes of storage space that you might need. So I genrally used it for storing of extra headboard that I had left over from a previous bed and such things, which do not require special protection, but definitely special size.