I’ve been stationed at Fort Hood three times and I have a rental there. Is there turnover with Soldier tenants? Yes, of course. But with the constant influx of new personnel a good property won’t stay vacant. A lot of folks stay in the area after they get out to work Civilian or contractor jobs on post too. Out of six or seven tenants I’ve had I think only one or two were Army. The area also has other things going for it (e.g. a growing Texas A&M campus, the main highway being upgraded to I-14, etc). Other local cities are good investment locations too (Harker Heights, Copperas Cove, etc). At some point I’ll invest there again.
My property has been a rental for +/- 15 years. But it was a house hack mobile home (I wish I knew about REI back then and I would have made a better purchase).
Anyways, a SFH I owned there in the area gained 9% in five years when I sold it. The appreciation overall is low to average I would guess but you can find good deals that will cash flow.
Looking at some statistics on rent. Killeen vacancy rate is higher than Texas and US. Rents are low relative to Texas median.