We've just started the 2nd quarter against the Jazz as I write this, and Roy looks as good as he as looked in months. Why? Because he is not being forced to play back-up pg. If you don't want to use any of the actual back-up pg's (by which I mean Mills or Armon) then use Fernandez, because Roy's performance suffers at the pg, unless he is playing against a noticeably physically weaker player.
To sum up, I hate using Roy as a back-up pg!
Also I believe (and I haven't actually looked at any stats so I might be wrong) that Roy plays better with Mills on court.