I have, a couple years ago, but not since pre-COVID. Used it for 2–2½ months.
1) security – the place was fenced (one story) and of course each unit had its own lock – we spent a bunch of $$ on a high end lock. Managers lived on the premises. Never had an issue.
2) Heat – this was a storage place with garage doors to the outside – not an indoor place. Our storage was in the April to June time frame so heat wasn’t an issue for us. However, it could have been in mid-July. By the way, this was all in Atlanta, known for hot summers.
3) Pricing: Some places will do “first month free” offers, or something like that. Shop around/
4) Are you going to need anything that is being stored? Put that stuff near the front of the unit. Or better yet don’t store it. I had to find something (when I had the unit) and it was a pain in the ass to empty ¼ of the unit to get to it.
5) Check on the driveways and how close you can get to the door. The place that I used was on a mild hill, meaning that the truck (U-Haul) was on a slight incline. In retrospect, I should have rented on a totally flat section.