I've got back problems. Bulged disc, degenerative disc disease, whatever they want to call it. When I built the Rat Turd I picked a seat that fit my ass. I trimmed it so it fit just right. I mounted the seat with its own pair of nitrogen filled shocks. I placed the hiway pegs in a spot that allows my spine to bend in such a way that it takes pressure off my nerves. I made the handlebars with just the right bends to be comfortable for me. I rode this bike three thousand miles in one week last year on vacation. It works for me and my back feels better after a ride.
Here is a pic of the cast iron seat on the bike. It looks like torture but that's not the case at all.
If someone that rides is truly curious then I offer all the info I just stated above. I was already running a little behind so as I was walking away I just told him "The key is in it. Find out for yourself".
When I came back out the bike was right where I left it. I guess Mr. Knowitall didn't take me up on my offer.
Moral of the story...Keep an open mind and don't be a dick.