Very good question Scoobs, I don't want to go off topic too much on this thread, but I guess I'll bite for this one post.
I don't want to sound too cliche, but I think of joining the Air Force as broadening my career. I'm an aviation professional. I'm absolutely fascinated with combat aviation as I always have been, and although the Apache is a hell of a machine, the Army's focus is and always will be the ground force. I would also very much like to be an O-grade officer, but when you do that in the Army, you will fly significantly less. (For more on that topic, take a look at threads like Army Vs. Air Force Flying, etc.).
This isn't my first day as an adult and I understand that there will be politics and organizational issues everywhere you go, but I have spent a good deal of my time in the Army working with the Air Force, and I can say my experience with their side of the house has been much more enjoyable. I understand the difference between personal and professional opinions, and much of this falls under the "personal" side. If a unit was asking me this question during a board, I would be sure to stick to the "professional" side.
I'd say the main reason most people want to make the switch is that The Army is a huge, general-purpose ground force, and it's command focus is oriented toward that. This creates a huge lack of understanding on how to run an aviation organization. Sometimes you get really good aviation commanders like Gen. Cody who understand how to manage it, but most of the time you are under the command of a non-aviation commander. Sometimes that makes for minor safety issues, like having pilots participate in mandatory ruck runs (as if the health risk is worth the physical fitness), because the post commander said "all units will...etc.". Sometimes it's a major issue, like switching to a two piece "flight suit," which actually costs more than keeping the nomex pickle suit, and isn't really fire retardant. All because a Sergeant Major thought the pickle suit was a "Status Symbol" and no one who was making the polices knew better.
From a strategic perspective, this issue manifests itself in different ways. For example, the Army will often fall behind the Air Force in some very important technologies, like how we use BFT instead of LINK16. Or our mission planning software, which is basically a modified version of an old software program that the Air Force developed a long time ago and has since moved beyond. Also, when the Air Force literally asks us to participate in some JAAT or CAS training, our command isn't very concerned or helpful at all and doesn't work with us much. We pretty much have to make it happen on our own time by squeezing it in when able. Such training is immensely important in our modern Joint-Tactics focused war strategy. I guess part of it is a pride thing between Army ground force commanders and the other branches.
And yes, in my situation, the allure of a fighter jet is incredible. The power, performance, mission, everything. I sat in an F-16 cockpit while I was talking to some Viper guys about CAS training and sensor feeds, and that is my kind of office. Singe pilot, excellent view, plenty of firepower. I don't care if pulling Gs is a little uncomfortable and I have to stay in shape, sign me up!
But anyway there you go, back to the topic I guess!