Anyone that has a Gen 3 will know the factory seat is a plank. I picked up a tip chatting to a V-Strom owner a couple of weeks ago, he had a 'Sit & Fly' seat cover and I asked him about it.
It's like a stretchy, springy mesh that covers the seat and fastens with velcro.
The mesh lets air circulate under your bum and thighs so they don't get sweaty and the springiness adds a lot of cushioning.
I've done a couple of 150-mile rides on mine now and the difference is striking:
my @rse didn't go to sleep (which it used to) and I wasn't constantly shifting around to relieve pressure and aches.
Best of all, it's $27 (£21) INCLUDING postage from Israel. Mine took 5 days to arrive. The small (S) size works fine on the SV seat, it stretches just right.
https://www.sitandfly.com/