Truth be told, I have never been comfortable in a normal chair, sitting still, two feet on the floor. It's so confining and conformist!
I am more the cross-legged, both feet under me, one leg under me, one-leg-sprawled, feet-on-the-desk type. I thought I might outgrow that and learn to sit "properly", but I don't see that happening. Currently I alternate between a cushioned backless stool (to my left) and my very attractive decor-matching stability ball. It's just enough freedom and movement to keep me happy.
Then why sit when you can lounge?
And for the really lazy....or overtrained. Now THIS chair has some promise!