He is considered by his peers to be the BEST coach in the nation at doing the most with the least talent, and to be among the best strategists in the entire game.
So his peers think he's one of the best, and the fact that he's had more success at FOUR schools than those programs had had recently (or ever) agrees. That this year's edition of Michigan, picked to finish DEAD LAST in the B1G, is knocking on the door of the tournament suggests many of the same things.
Is he the best recruiter in the world? No, but he's better than it first appeared. Would I rather have Izzo? Sure, him and another 5-6 guys (Coach K, Roy Williams, Self, etc.). But anyone else who is doing "better" than JB is not facing the recruiting restrictions he does here (from a facilities, recent history, and inability to cheat standard). In a single game for my life between two teams with equal talent, I'd take him over all but a few coaches. So yeah, one of the best.