I needed a chair 15 years ago when the Aeron was the hot thing. I tried one out and didn't like it. After testing half-a-dozen different chairs I ended up with a Steelcase Leap. I'm still using it today and it's held up really well. After about 12 years daily use the gas cylinder finally failed. It was still under warranty so a service person came to my office and replaced it for free.
I don't know exactly the reason I felt so good on Spinalis as it was several years ago. But I do know it was "different" than any other chair I tried (haven't tried many).
Hope it helps.
I've had the aeron for over a year and I absolutely love it
Ikea has some decent chairs, go in and test them out. The one I liked best was one of their least expensive ones.