I bought a used Steelcase Leap chair about 6 months ago for $600. At the time I was a little disappointed.
My old chair was more comfortable. I had modified a cheap old chair, replaced the armrest supports to correct the height and heavily padded the new armrests. I really like to anchor my elbows when I type and the setup worked really well. Unfortunately, it was an old chair and the fabric was hard to keep clean so it always looked dirty. I thought about reupholstering it but that was beyond my expertise and not cost effective to have done so I took the 'Leap'.
The feature I like the most about the Leap is also its curse. The fully adjustable arms can move anywhere; up and down, in and out, forward and back, they can even rotate and that's the problem. They tend to move without prompting. They slide out when I unintentionally apply lateral force and they twist at their own discretion. It's probably my own fault. I squirm around more than a 4 year old boy with pinworms. The telescoping height adjustment tends have to much slop in it so it wobbles which isn't a problem but it seems cheap for an expensive chair. Because it was bought used, I have wondered if its former owner used it as a pommel horse or something.
Recently I was using my wife's computer and I was surprised by how bad her chair felt. With all my focused attention on the shortcomings of my chair I forgot how pleasant my Leap is to sit in. The chair is firm but seems to promote good sitting posture, has a fully adjustable lumbar support and I rarely have pain when sitting in it for extended periods of time. The leather is also easy to keep clean which is important for me because I am often dusty from work- think Pigpen from the Peanuts comics.
I will one day probably modify the arms; shim the telescoping glides with teflon strips, lock the rotating feature in one place, create more resistance to the lateral adjustment and add padding and reupholster the cushions. Maybe then I will stop complaining.
My recommendation- Try out the chair before you buy. One size rarely fits all and we all have different needs.