I'm surprised people are debating Ray's effectiveness.
First, he's been by far our most efficient offensive player. There's a question about whether he's getting enough shots in the offense, but there's no doubt that when he takes shots, he makes them at a more efficient rate than anybody else on the team.
Defensively, at least through January 18 he'd held opponents to a 9.9 PER and a .437 eFG%. To date, opponents are shooting 38.7% when he's covering them. He's not a ball hawk like Bradley is, but opposing SGs aren't lighting him up, either.