Here is my views because I visited both locations. Warwick Campus is like a small city and well organized campus, however; do not assume that prices of services inside the campus is cheaper, for example food or beverages, it is a monopoly inside the campus where monopolists always dictate prices. Birmingham is a city and the competition between services providers is high which works for people's benefit. So, do not expect Warwick is a city style, once you get acquainted with the location in few weeks, it will start to be boring.
For education, Birmingham is not less than Warwick. Future employment is heavily dependent on the interview and how to present yourself to employers. Employers look for two things in equal measures: First is Knowledge (both Universities will provide it), and Second is Behavior and underline the second. Behavior (you have to act like an employer), meaning employers' goals must match your personal goals, forget about teamwork, attitude, etc these are pre-requisites for any job. The more you add value to the employer, the more the employer will add to your price. As long as you think like employer how to make money and pay your workforces, the more the employer will invest in you and promote you to higher levels.
For me, I will go with Birmingham! Cities will teach me things universities cannot provide especially if you are away from your family. For me, Warwick is like 3 years imprisonment counting for its end. However, for others it might be the opposite, it is all about your personality lifestyle and preferences. No one can answer this question except You.