Self-storage facility - what to look for when inspecting?

[Erik W.]

I am looking to purchase a self-storage facility that was constructed in 2005.  It consists of a mix of 5x10, 10x10, and 10x20 units.  All are presently leased via an electronic "kiosk" style system, which also handled payment and leasing duties.  There is also a 2,000 sq ft retail building on site that is leased by a tenant who does computer and cell phone repair.  All units appear to be under market rents, which is probably why they are 100% leased.  This is in a bedroom community of my hometown that has a city population of around 20,000 and a metro area population of 250,000.  Storage is a hot commodity around here.  They are slightly off the main road, but on a decent side road that sees probably 2,000 - 3,000 cars daily.  There is presently no fencing or security cameras that I'm aware of, but I will verify that.  Parking and space around it is paved asphalt.

I am going to physically inspect the property soon.  What things should I look for regarding the condition of the metal storage unit structures themselves?