After I bought my f6b I thought I was going to have to sell it right away because my knees hurt too much with the leg position which was the reason for selling my ST1300 and getting the f6b in the first place. Before selling the B though, I installed the Kuryakyn II forward foot pegs and bingo, my leg discomfort was gone. With those foot pegs I can sit in four different positions including bracing my feet against the pegs, straightening my legs completely and getting the bottom of my butt off the seat, leaning back against the rise. I also have a mesh pad on top of the stock seat and with this combination, at 62 years old, I can ride all day.
Good luck