Yeah, the PX-100 II has decent bass for such a small headphone. I really enjoyed using it.It's been some years since I heard the the PX-100 II, so I don't remember too well.
But I do remember when I lost my original PX-100 I ordered the PX-100 II -- I sent that one back after one day and I purchase a NOS PX-100...which I still own and love.
I think that the bass was bloated (compared to the first version). I do remember thinking that they were not bad headphones, but just not legendary, like the original PX-100.
I wish Sennheiser would consider making a new revision of these iconic headphones. With detachable cables, perhaps? I'd buy them in a heartbeat!