My 3030 seat sucks as well. I had a JD4200 before and I could sit in that seat all day. I complained to the dealer and he is suppose to be looking into it. I think Kubota is having a dealer meeting this week. I looked at the seat from an L series and they seem much more comfortable. The mounting holes also look like they will match up. Not sure about the arm rest but I don't use those anyway. I doubt that the shims will do much good since I think it is a design flaw. All the new B series seem to have the same seat design. If Kubota doesn't fix it I will buy another seat. I love everything else about this tractor.