Pros
The training and (currently) benefits are nearly impossible to beat. You will be thoroughly trained to do your job (though the quality of your on-the-job training will depend on where you end up). So long as most of the current benefits continue, you will have the best medical coverage (for you and your dependents) available, along with access to excellent education benefits (including, most of the time, full tuition reimbursement), free legal services, the commissary (discounted grocery store), AAFES Exchange Services, and so much more. They will effectively force you to stay in shape and keep your life in order. Even after your service is complete there are hundreds of veterans benefits that you can continue to enjoy. Seriously, a quick search on military benefits yields far more than I can list here. If you are considering a career in the military then I'm sure you're familiar with at least a few of the benefits.
Cons
Military culture is not for everyone. It's difficult to describe here, but you will have a hard time fitting in if you like to ask questions, understand reasons for things, and work efficiently. Additionally, when you sign up for military service, you are not getting into a 9-5 job. You are signing up for a way of life. They move you wherever they need you. They deploy you, sometimes with little notice. They expect you to behave according to their values (which aren't bad values) on and off duty. The military invades every aspect of your life. This isn't OK for some people. I didn't have much of a problem with that aspect of it though. For me the real issue was the fitness program and the military mentality. The fitness program requires that you are able to run a mile and a half within a certain time (based on age) and perform a minimum number of push-ups & sit-ups within a minute time limit each. For some people these are not a problem. For others they will ruin your career. If you aren't already in the habit of exercising daily (to include running) I'd be wary of joining. Additionally, even if you do exercise, the fitness test can make people nervous (they get performance anxiety). If you get test anxiety of any kind, the fitness test might be tough for you regardless of fitness levels. Finally, the military mentality clashes with certain people. As before, this is a little difficult to put into words, so I can't promise you'll be able to make a decision off my input. Basically, there are three kinds of people in the military. Those who thrive, those who survive, and those who don't stand a chance. Those who thrive tend to be the kinds of people who can be very proud of their country and their work. I don't want to insult anyone, but a lot of people in this category don't question things and tend to accept what they are told as complete fact. Then there are those who survive. I was in this category until the fitness testing caught up with me. These people can adapt well to new situations, including learning to be OK with a work environment where people don't always understand what they are doing or why they are doing it. They can work around problems that arise from terrible communication skills and inefficient work procedures. Some of them will last through one enlistment, others will survive a 30 year career. At the end of it though, I believe they will all feel like a little of their soul has been sucked from them. The final category is those who don't stand a chance. These people sometimes drop out in basic training (failure to adapt). Often they do something stupid and get kicked out administratively. They will rarely make it to the end of their first commitment, but if they get some good leadership they may make it a little longer. Even if they manage to nearly graduate to the "surviving" category, I would not recommend that these people stay in unless they are seriously committed to meeting the needs of the Air Force. The Air Force is a corporation that does not care about you as an individual. Your supervisor may care, or someone else may take you under their wing, but ultimately you work for the US Air Force and they do not care. Don't let the benefits package fool you into thinking they care.