Birmingham is a little city. It has good weather, not really getting any colder than freezing during the winter, and never getting any colder than -6 degrees. Summers are sweltering, hot and humid. The city has about 212K people, and about 1.1 million in the metro. About the same size as OKC, maybe just a bit smaller.
Not a lot of aviation around, with rentals costing about $130 or so an hour for a Cessna 172. That sucks. At least here I can get a Cessna 172 with G1000 for about $150 a hour.
There is at least one place to train, but I don't know anything about the guy. Apparently he is a BB from Sau Paulo, but my current instructor doesn't know who he is. Not good
There is some work around town, but not as much as I would like. Finding a job that pays the same would be very very tough.
Taxes in AL are low, not more than 5% at the most. State sales tax tacks on another 5% to each purchase. Property taxes are low as well.
Birmingham, AL is one of the very few places that is actually cheaper to live in than OKC. Birmingham is about 2% less expensive to live in than OKC. That is a good thing.
Alabama is a shall issue state so CCW is no issue.
All in all, I would be treading water for another 3 years in Birmingham. I wouldn't be moving my career, training, or hobbies forward, but I likely wouldn't be going backward either. Birmingham, however, is a bit more of a jerkwater hell hole than is OKC, if that is possible.