In his specific arena, he is either the greatest or second greatest shooter of all-time, depending on how you mix him and Reggie Miller. And he hit arguably the greatest shot in NBA Finals history, clearly in the top ten and probably at least in the top five, and definitely the most memorable shot in recent seasons.
Honestly, to me, even though I've always felt Ray was clearly the better player, the one thing I thought separated he and Reggie from a historical standpoint was that Reggie had that comeback clip against the Knicks that could be played forever and Ray didn't really have that one defining clip... after that 2013 championship, he has it.