Tony is fairly better than Ross when he's playing well. But he's also worse by a good margin when he's not playing well. Ross' production is more dependable, he doesn't oscillate as much as Tony Allen.
Ross's overall offensive numbers are much worse that Tony's aside from turnovers. Even if he's more dependable his "steady average" would probably be worse than most of Tony's games.
I still wish we signed Ross over TA. He only would have cost the minimum too. Ross doesn't have much offense, but his mid range shot is better than Tony's. Ross is also a much better defender - he doesn't gamble like Allen. Tony's advantage is that he can attack the basket. ...But only does it well every 3 or 4 games.
Side track: This summer the C's should grab Ross, and then ship Scal, TA and House's expiring contracts for a really good 2 way player.