in a crash at a certain speed, a good crash bung HAS TO bend a bit, if the bolts are too stiff, they'll either dent your frame or snap.. and no, you can't ever compare two crashes, every single one is different.
to give you my opinion about them, i'll try to explain it this way:
if the motrax would be offered to me for free today, i wouldn't fit them.
at the same time, if the R&G's would cost me 200 quid, i'd still buy them in a split second.
and that's because of years experience, 'testing (read; crashing)' with them, on both road and track...
R&G's saved my racebikes on at leat 10 occasions.... 'nuff said...
edit: the ones that motrax do now, aren't even top blocks anymore... top block sued them because motrax had their stuff copied in china.. after first selling the top blocks..