It depends on how the Trust wants to focus its funds. Similar to how a VC fund might focus on enterprise software or B2C. For a reference of Self-Storage REITs, this is a good start(1).

Different markets are definitely hotter than others. Houston, Miami, Austin, Los Angeles are some of the more lucrative markets, but even small markets have strong players. Self-storage is fairly democratic in the markets served. I've visited facilities in rural town that are wildly successful for the owners, as well as small facilities outside of Manhattan Beach.

(1) https://www.reit.com/what-reit/reit-sectors/self-storage-rei...