it would indeed be a nice design of a perk, only if it wasnt breed locked and be at least comparable in stat bonuses to any other breeds genome perks,,,
lets make a fast comparison to just one solitus perk, wich comes handy in this case, since it gives aao aswell:
sphere +100aao( and 100 aad) vs. +1.5kaao mongo rage
15 times higher, breed locked bonus,,,
the drawback, when it comes at the end of MR duration, is way to little of a drawback for such a huge boost, lets face it: +1,5k ar within ao's mechanics is huge
so huge it allows to use ( with great success ) in some cases weapon/specials combinations you would never even dream of landing anything besides a on a backyard leet w.o MR
if you compare the drawbacks to the stats gain and anything else in the DataBase, the drawbacks look minor at best, and that boost is in many sittuations gamebreaking ( not in all, but in enuff to deserve a redesign/tune down )