i'm thinking of buying one of these for my rifle, it'll be used for lamping and long range magpie/grey crow/rabbit shooting, just havent made my mind up on the 72mm or 56mm obj, i've shopped around and can get an ex demo 72mm model for d same price as a new 56mm but i don't know which to go for, the 72mm is surely better but will be mor expensive to mount due to d 34mm tube and i'll need a comb raiser due to the extra height of the scope, is there much difference between d optical quality of them, any advice will be greatly appreciated,