I guess seat discussions are like oil topics....
To me it not only depends on the shape of the seat but, IMHO, also the position of the seat as in leaning too far forward or not high enough..
My first new bike was a 2004 R1150 RT (bought in 2003) that had the perfect seat in the perfect position and I didn't even use a pad or anything. That was a great set-up.
The next bike I had, was a 2005 K1200LT and I still want to shoot the a'hole that "designed" the seat on that bike. Totally useless after about an hour, so off it came and I had Rocky Mayer make me one that was perfect. Several 1000 mile days proved that to me...
Next came a 2006 R1150 GSA that required a pad but was fine for the 88K I put on that bike.
Flash forward to 2017 with a R1200 RT who's seat was fine, after a redesign of the front mounting point so my nuts wouldn't be riding on the tank.
Form and shape were fine, no further adjustments needed. Sadly the riding position on that bike sucked as the bike felt cramped even after lowering the foot-pegs and raising the seat. My knees protested all the time..
Traded the RT for my current bike, a 2018 R1200GSA which has a Sargent seat and either a Bead-rider or WildAss pad depending on how many hours I ride. Last summer I did several 800 mile days to Great Falls and I was relatively ok, at least physically....