Seat comparison:

Stock vs. Corbin vs. Sargent (my Sargent, anyway)

For the record, I'm 6'1, 185, 34" inseam. The height & weight of the big Sabre have not been a problem for me. Stock seat: 14 year old foam just doesn't do it for more than 30 minutes at a time. The rear portion of the seat lets the passenger slide around all too much. From the front of the seat to the stock pegs is 19", from the rear seat to the rear pegs is 16".

Corbin:

The foam is very firm, almost like sitting on a board. Allows you to get pressure off/circulation flowing with slight movements. Does not absorb shock from rough roads at all well. The front of the seat - pegs measures 18". The rear of the drivers portion is 1-1/2" lower than stock. The drivers portion is flat, and wider than stock. This can cause problems for people with a short inseam, as short legs have to bow out more than long ones, leaving less of them to reach toward terra firma. From the rear seat to the pegs is 17", with a slight scoop. The firmness of the foam brings air between seat & rump when going over bumps, preventing the grippy material from doing it's job. The Corbin is probably the best for a drag racer, since the lower height lowers the cg, and the pronounced step keeps you from sliding off the back ;-)

Sargent:

They do anything from stock recover only to as elaborate of modifications as you can describe. What I had done was: Griptex cover, super-cell foam front & rear, stock shape for drivers portion, raise rear portion 1", widen, and add a dish. It took 2 tries due to a mis-communication, so I was on a borrowed seat for a whole month (thanks, Dan!). Now that it's back, it looks very good. I did _not_ want a lower seat, my knees were bent enough as is (I also didn't want to lower the pegs), and I wanted a bit more cushion on the rear. From the front of the seat to the pegs is 19-1/2", while the back is 1/2" lower than stock. Regardless of the measurements, with the stiffer foam it's actually higher in practice because it doesn't compress as much. I now have to pay attention when putting my feet down on sloping ground. The rear portion is the same height (17") and shape as the Corbin , but is more compliant. Raising the rear made a nice little step at the rear of the drivers portion, helping you to stay in place on takeoff.

The Corbin gives the bike a smaller, lighter feel, along with a shorter reach to the ground and footpegs. For me, the Sargent is the best fit, as the added height is not so much as to be a problem, and gives me a bit more legroom on long trips.

One maker of high quality custom seats is Bill Mayer. The foam he uses is not quite as hard as Corbin, but still firmer than what is available from Sargent.