Iv been interested it these for some time now but im not shore what to think of them? They look smart but im concerned that they have 4 paws in them but ONLY 2 are engaged at any one time. Witch i don't see the point it that? Also concerning me is that im not shore that they would stand up to much constant abuse from big gaps and side hops? Also witch hub shell would be strongest as GU/ZOO/ECHO/ADAMANT all have made different shaped hub shells? Has any one got any thurts on this one?