Those chairs look cool but they also look like they'd force the head forwards (because of a high back). I had a similar chair for a while and all I got from it was a neck strain that I still haven't completely recovered from. But it depends on your body shape and how long you intend to sit in it. If it's hours on end, try to avoid the "ergonomically designed" chairs. I think they're designed by MDs who want you to visit their clinics.