Hi Tomson
On my old XL and my current FL I use Mustang. They use hard foam that settles in after some time to be very comfortable, and they have the best customer service imo:
I have the RK 2-piece touring seat on my current bike, and the passenger pad used to interfer with the saddlebag lids (old type). I therefore lost a couple of the black studs and wrote to them to buy new ones. They immediately sent me a small bag full - free of charge (I was in Korea at the time, so shipping there cost them a fair bit)!
In addition they are reasonably priced, so unless you want a leather seat (like Corbin) and your old is too worn, there is no question what I would choose...