The Good: looks great, plastic slides well on anything
The Bad: plastic portion wears down way to quickly and deforms
was pretty psyched when I put these on my bike but was then completely disappointed in them about an hour into the first session at my local skatepark when they showed excessive wear, about the equivalent of 6 months heavy use on aaluminum guard. On top of that, the inner lip had deformed causing it to rub on my spokes forcing me to removed them completely and put my cheaper, more functional Gsport Glands back on.
BSD should revise them and either make it full aluminum, or even better make the "sleeve" portion out of chromoly so they still slide well.