RE: What do you consider.... (big buck)
In my state (NC) our bowhunting association (NCBA) recognizes any buck over 100" as a "book" buck. I'll concur that a 100" buck in MY part of the state is, indeed, a GOOD buck.
I've never seen one that would go over 100" (other than the one I took, las year). It's hard for me to have an opinion on "great" and "monster".