: You might have to make two seats to get it right.

Why? Minicell is a great medium to work in. It's easy to remove material, or to add it. No one ever said that a seat had to be carved out of a solid piece, then left alone. Personally, I prefer to build my seats up from thinner layers of foam, as it allows for lots of flexibility and experimentation, plus the thinner foam (1/4" - 1") is cheaper and much easier to find than the thicker stuff (2"+). Also, there's no reason that the seat bottom, hip pads and backrest have to be one assembly. I find that there are advantages to keeping them separate.

Please don't take this a negative comment on Joe's seats. They look fantastic and I'm sure they're worth every bit of the price. I just wanted to point out that there are other alternatives and that making a comfortable seat isn't exactly "rocket science".