I bought my RoadGlide in Anticipation for a Coast to Coast Nationwide Road Trip planned for next year. This will give me time to pick up the necessary mods to improve my comfort for the ride and the stock seat will definitely have to go. I've bounced through the threads here, but I'd like to know if anyone with extreme long ride experience could chime in and make suggestions.
Here is the deal about seats. Everyone is built different and finds different seats to their liking. For every seat that is recommended there will be those who found that seat unbearable.
If you have a good local Harley dealer, they should have demo seats available for you to try. This will at least give you an idea of different seating available and whether you like cushy or firm seats better.
Make sure you go for a long enough ride to get the feel for the seat. I would do a 60 mile to a lunch spot and then return.
The worst seat for me was the Harley Hammock seat, but you will hear from many who loved it. I think it depends on your weight and body shape.
I really like the Low Tour Solo seat and use that most of the time on the bike, but it does require your legs to be flexible. What I like about it is that I can put my sheepskin pelt and/or my airhawk cushion on it to change up the pressure points.
I also have a Corbin Heated Dual Tour with backrest that I put on in the winter. It requires me to have a taller windshield and totally changes the riding position. It is a firm seat and Corbin recommends 1000 miles to break it in.
The stock Road Glide Ultra seat was way too soft for me so after the first 50 miles I felt like I had sunk down to the pan and it pushed me too far forward.
For me the main think on a long ride is the ability to change positions so you change the pressure points on your rear. I added extended length floorboards to allow me to move my feet around and went with highway boards instead of pegs for more movement.
For High Speed riding many prefer having the hard lowers installed to keep the wind from beating on your legs. I remove mine in the summer and put them back on for the winter.