I HATE these chairs too. However, someone recently told me that they come in different sizes, so maybe mine was just the wrong size for me. I've also heard that what seems comfortable might not be best for you too.
I'm most comfortable with the no support option. You can convert either of the other two to this option by removing the black thing (it slides off sort of).
As far as sizes go, most tall and/or slightly overweight men need the C sized one, but definitely get a proper sized one.
If you go to high end office stores (sam flax here in atlanta) they'll have a few different sizes.