I find the seat on my ST2 quite comfy for long trips but as we are all different sizes what is great for one can be literally a pain for someone else.
I have heard good things about Corbin seats and I have one that I shall fit this week, I'll let you know when I have given it a try out.
I did a 3500mile trip last year on the bike,England,Italy,Spain,England. and the only discomfort was caused by the COMFORT kit, goes to show "don't believe what the ad's say" try it out before you do a big trip.
Just got back from Catalunya.......Nice one Loris.....