beware on the force guards. Try before you buy and take you boots with you. They are pretty big. I can't even close my SG-1's with them on. I have large calves. They did work with my Alpinestar's though, but just barly. They also dug into my shin a bit at the bottom and the left one tended to move down a bit and pinch my skin on the knee. Other than they are great. The protection they offer is one of the best as far as knee pads. I also have TKM AXO guards, they a little lighter on protection but will work with my new boots.
If I had the money it would definatly be the Cells for me.