Yes they can - I have a Sargent on the KLR650 in Aus and don't need anything else for long days.
The Beadrider was a must have on the ST1100 and I think the main advantage is breathing and less you squirm around easily.
I'm going to Spain for three weeks later in May - you are welcome to borrow the bead rider tho it might be big for your bike - it's 14x14
It's weird as it feels too hard when you get on it and you figure it's gonna hurt over time - but it doesn't.
The Sergant is very good - I was surprised - I bought mainly to lower the KLR a bit so I could use the bead rider but turned out I did not need it.
I've heard very good things about the Corbin and the DayLong is just superb but $$
Worth the effort to get it right. Sometimes 1" risers can shift your riding position nicely as well - the 1" up and back on the St1100 made a big difference for cheap.
I've had good luck with both the Sargent custom seats and their World Sport Seat. Not so much with the Corbin due to poor fit, poor manufacturing quality (in my opinion), and because they weigh a Metric tonne.