Perhaps your back issues are more sever than most people who also have back issues?
Personally, I've had the Markus for some time and have never had to get up off it due to issues. I actually like the mesh back that seems to form itself around my back as I lean back as opposed to hard back chairs that are quite stiff.
Currently testing the noblechairs real leather one, and it's pretty supportive, like sitting in a car seat from a premium marque. I also like the armrest, which I think are often overlooked by people who buy cheaper chairs without this feature. Being able to adjust the pivot, strafe and height of the armrest is pretty vital for ideal arm positioning.
As I sit here right now using the mouse, the height of the armrest is set to the same as my desk, so my arms have a soft rest to be level with rather than no place to rest them fully.
I do prefer chairs with mesh back, though. I like the "breathable" backrest in those chairs. I'll be looking to upgrade to one of those ergonomic ones with a skeleton spine behind a mesh back. not cheap, but worth it in the long run.