If it's anything like the HS-15, then yes, you can expect a huge comfort boost over the PX100-II. I didn't find the PX100-II all too comfortable, and ended up snapping the drivers off the headband in attempt to mnake them clamp less.
A shame, the PX100-II is FREAKING PHENOMENAL in sound quality for the price.
That's good to hear. I didn't either, they pressed against my earstoo hard into the driver units causing physical pain. They resist having their clamp reduced after having them for like a year and many stretching attemps they still haven't really reduced in clamp, my head is too big for them, I ended up just giving them to my mom.
The PX-100 ii was one of the few Senns I actually liked and I do miss it some but I never used it much because of comfort.