Oklahoma City proper is about 620 square miles. The surrounding cities make a metro area that more than doubles the population.
It really depends on what type of housing you want to live in, you budget, what length of commute, and the lifestyle/hobbies you want to like near. There are places to fit about anything within a 30 minute commute.
I'm assuming you are going to stationed at Tinker. Del City and Midwest City are both next to the base. Both have both good and bad areas of town in them. There are more rural areas to the east of the base.
The tornado in Moore is going to greatly impact a lot of available housing in south Oklahoma City for the next 6 months to a year. I should also have some impact in further reaching areas.
I think you will enjoy it here. The cost of living is very good. I've worked on the base over 30 years and have found many military members end up staying here in the area after retirement because of the economy and people.