I've experienced the "lip" issue on the Aeron - the transition between the mesh and the hard frame was very uncomfortable for me. I'd also recommend the Leap.

I've experienced the "lip" issue on the Aeron - the transition between the mesh and the hard frame was very uncomfortable for me. I'd also recommend the Leap. It was the first purchase I made when I started working from home - worth every penny. I have a V1, I haven't tried a V2.