Some people in my group like those "air" seats, I forget their proper name.Well, it is not cheap, that's for certain. However, the seat cost is about 5% the cost of a new CB-500F. It is frustrating that Honda has fitted the CB-500s with sub-standard seats; it costs no more to design and build a very good seat than a poor seat. It's all a matter of shape and foam firmness and density. Over the years, I have modified some unpleasant OEM seats into good seats with just an electric carving knife (after removing the seat cover!). The CB's seat is too thin to allow successful re-shaping, unfortunately, but it still can be repositioned to delete much of the downward slant.
I rode my '17 F model 217 miles today and the last 60 miles reminded me that the suspension, even with an up-scale Wilbers, was still too harsh. The firmness of the Corbin seat was no advantage, either. I'll try a sheepskin seat pad after this. It's hard to buy production line seats, as they are good for many purchasers and not so good for many others. I'm very slight of build, 134#, and my suspension/seating might be perfect for a rider 40# heavier, but not for me.