Sand:

Amen to everything Rick and Galaxy said.

Keep in mind: most civilians think "Guard" means the only part-time warrior. Reserve can be also...the difference is whether it is funded by the State (Guard) or Federal Governement (Reserve). Each branch also has full-timers, too. Two branches, minor sematics, transparent differences for most aspects of a career.

I initially wanted to fly heavies in the Air Force, and went fighter for the intensity of the flying. Doing so, I thought I had shot myself in the foot for future airline jobs. What I did not realize: fighter time is PIC. Heavy starts off not. Most major carriers use a multiplier for fighter time (rumor was United, American, and Delta multiplied by 2 for fighter time). They recognize that most of your time in a fighter is not on autopilot.

However, as rick posted, it can take some time to get used to a heavy airplane after spending a lot of time in nimble jets. My first airline training (747 classic) was humbling in the sim as I couldn't hold bank with 10 degrees or altitude within 300 feet for steep turns.

The best flying jobs I've ever had were military. I've enjoyed both, but if I had to pick one over the other: military. Pay and benefits are generally better too---not to mention job security (I'm leaving out the getting shot at part).