Herman Miller Mirra 2

I switched to a Herman Miller Mirra 2 which has great sacrum support (even better than an Aeron), and literally after the first work day of sitting it it, I feel so much better. I think I read somewhere that Herman Miller states that sacrum support is just as important as lumbar support for overall back health and I'm inclined to agree. It's like night and day how much better I feel now that I got rid of the Leap chair. Plus, the Mirra 2 has the best lumber adjuster that I've ever experienced in an office chair and I just feel so much more supported in it than the Leap (or even the original Aeron I had before the Leap).

I currently own the Herman Miller Mirra 2 and find it unbearable. It is causing immense coccyx pain to the point that I can’t sit at all. I presume this is due to the hard plastic design?.

I couldn't sit cross-legged in it at 6'1", but maybe you could. I swapped that one out for the Herman Miller Mirra (older model, not the newest mirra 2) which is a mesh chair. The back is substantially more firm than the Leap 2 since it's plastic with optional "butterfly" padded mesh covering it. Just keep your eyes out because some mirras do not have adjustable height armrests and firmness adjustment for lumbar if that's a concern.