Far better quality than 661, superb design. But for XC-trail use, with lots of climbing and miles of pedaling, a bit on the heavy side. Striaght out of box and trying them on, then scale comparison even to the 661 DH D30s, could see all of the above. Wish POC had a "Lite" version for use with my 100mm SID M429er! Was hoping to the replace the lower quality 661 XC pads, not the DHs.