I debated between the Russell Day Long and the Rick Mayer seats, both built in northern California. Both are built on the stock seat pan and both have an impeccable reputation with the Iron Butt guys. I believe the RDL is somewhat more popular. One Iron Butt guy told me that if their riders aren't on an RDL, they are on a Rick Mayer. Can't vouch for that myself. I went with the Rick Mayer because from conversations with both, it sounded like the RDL would put me a bit high for my 30 inch inseam. I also find the RM to be more attractive. Either builder will work with you individually. The Rick Mayer raised me a bit but not too much. I can still flat foot at stops. I also have the Utopia backrest which was installed for me by Rick as he built the seat. I had the Utopia and the stock passenger backrest recovered by Rick in the same material as the seat. In the end (pun intended) the result is determined by the butt. I can spend a full day in the saddle and find that I never give even a second thought to the seat or to my comfort. It's that good. I'm 72+ and comfort is important to me. I also have the Kury risers, Aero pegs, and for the best $10 you can ever spend, a Throttle Rocker.
The guy who invented the first wheel was an idiot -
the guy who invented the second one... he was the genius!
http://theringfinders.com/blog/Larry.Royal/