We bought some of these chairs at my last startup after trying quite a few "fancy" ones (including the Herman Miller Aerons), and these were definitely the best. The entire seat and back surface is filled with "bike seat" gel, which also feels great.
Not at all cheap (though I wouldn't get it at Amazon, I saw it elsewhere on the web for $200 less). Then again, if you're going to be spending hours and hours in a chair, it might be worth it... sort of like the argument for buying a nice/expensive mattress.
We bought two of these chairs from the company during liquidation (ahh, the memories) and one is still my primary office chair six years later. It's still very comfortable, better than any other office chair I've tried. Stop by and see what you think!
Roy has a review about our favorite furniture store. I have included a link
