In addition to gel, sheepskin, and beeds, there is also "air" in the cushion market. We have a couple AirHawks that we bought in Sturgis years ago. Those are pretty darn comfy too!

Seats (like pipes) have many options... Mustang seats are great too.

btw - we bought the AirHawks before our first Mustang seats.... but they co-exist just fine....