What I find interesting is that I also put my feet on my desk. I have ever since I started using computers in the late 70s. I'd sit with my feet on the desk with my Digital Equip. Corp. VT05, it just sucked that at that time I couldn't put the keyboard on my lap as I do now. As I type this, my feet are on my desk.
I've never gotten over that habit, and it used to annoy the hell out of some of my bosses when I worked in a corporate environment. I've heard it's better for your wrists anyway, that's my justification

. My only issue is that I tend to lean forward so my shoulders, neck and head are not resting on the back of the chair when the chair is leaning back so I get fatigued and sometimes get headaches. I too need to find a chair where I can lean back with my feet up but adjust the headrest forward.
Not that I could get my company to spring for an Aeron, but it doesn't look like it would work for me anyway, there doesn't appear to be a separate adjustable headrest that you can tilt forward while the chair is leaning back. I think most of these chair designers expect you to have good posture with your feet on the floor.