I originally ordered the "Elevated Steel Max" as I am tall, 6'5" Upon using it I found a few issues: One, it was way too tall for me, even with the spring removed. Two: the seat was too small, and I weigh 210 pounds. (I do not have a big butt) 3: On the slightest incline or floor slant this chair will take off rolling with you on it down that slant. After a few months I placed a new order for one set of five (5) ordinary "Robust Steel" legs and a "Big Boy" seat. What I got was the seat and only 1 of the 5 needed regular-sized legs. The $99.00 specifies you'll get 5 legs, NOT one. What did they expect me to do with one mis-matched shorter leg? I emailed Sales and they promptly sent me the additional 4 legs. I am now able to sit and use this chair more comfortably. As far as the excessive tendency to roll down hill, all the Sales can say is to use the locking wheels. That is not practical if you're moving around while working. So, while this chair is good, be very careful about your order and make 100% certain that your floor is Perfectly level. There must be no tilt on the floor whatsoever, otherwise take it from me, you'll be constantly rolling down that slope.