Not all humans sit alike.
At work, I've had an Herman Miller Aeron for about 18 months. It's a solid chair, as is the Think, the Leap, the Mirra... except for me. I don't sit completely upright, and I tend to have my posture degrade into a half-slouch at times. I need a very firm surface. Sometimes I tend to sit on one of my legs, and that non-uniform pressure eventually forces the thigh support foam out and onto the floor.
With this in mind, the Aeron, and the other aforementioned chairs, fall short since I don't fit the intended use case. It'd be like teaching me to "type correctly" despite being able to type at 90-100wpm with a horrible, bastardized technique.
I use an Eames molded armchair. It's polyethylene with aluminum wire legs. The arms are at the perfect height, and provide enough support, but the polyethylene still has enough flex in it. It shrugs off my shoes. And it's much cheaper than any of the other chairs, will outlive me, as well as being better looking and 100% recyclable. If you presented it as an original option, I wouldn't of even considered it. However after hours and hours of sitting in chairs, I struggle to think of one that might suit me better.
I also don't have lounge chairs that force an upright posture (van de Rohe's "Barcelona", and Jacobsen's "Egg" come to mind). Sometimes I want to slouch, even if I'm talking to you. And when no one's around, I guarantee you I'll be slouching.
