Which Task Chair is Best? Ask UNC
The University of North Carolina did an exhaustive study of today's task chairs and published the results on their Environment, Health, and Safey site.
This study has it's faults, and it missing some of the models that you might be considering, but it can be an extremely useful tool if you are in the market for a chair. Due to their size, weight, and price, it can be extremely difficult to test more than two or three task chairs before making your purchase (the majority of your research will have to be done on the internet) so studies like this can come in handy.
So what was their choice? Surprisingly, it was the Neutral Posture 5500. This is an unassuming looking chair that does not have any of the flash of models like the Aeron, but UNC's testers liked it a lot (it rated at 88%). Number 2, at 77%, was the Transit from Sit-On-It. This is another short, plain looking chair but they did really like the armrests. This price for this model (with their state contract) was just $249, so that was probably a factor.
Number three, at 76%, was the first model that you have probably seen before, the Mirra from Herman Miller. This is a stylish, high-performance task chair with lots of features and a reasonable price. It earned top marks for lumbar support and actually seems to rank higher than the Transit.
Other big name chairs that were evaluated were the Humanscale Freedom (70%) and Knoll Life (65%). The testers were tough on both though- the Freedom was rated highly for it's back support, but got the lowest possible score for its lumbar adjustment. The Life earned the lowest rating for back support, but apparently has great directions. The testers' opinion put the Freedom it at "good" while the Life was "average".
It should be noted that the only chair in the test to get a score of "very good" from the testers was the Hag Credo 3400.
Read the rest of the test here.
