Go Guard/Reserve. That way you are guaranteed what aircraft/mission you will do. It's somewhat tougher because you will do personal interviews with hiring boards, but if you go active duty AF you have a great chance of spending a large part of your 10 year commitment in a GCS trailer not actually flying. I speak from experience.
The time I had in C-17s was awesome, and some of the best few years of my life. It's all about timing, and when I came up for a follow on assignment, the Air Force needed bodies to fill GCS's so that's where I wound up. 10 years is too long to sign away and not be flying airplanes in my opinion. Go guard/reserve.