could your calling range on button be far far wider than co?
I personally call a lot from the button and i feel good when i do so but thats not the case for the co , i always get a headache when i get called from the button and the chance to face more players on the pot increases.
Far better? Probably. Reasoning: acting last on 3/4 betting rounds is the best possible position. BTN guarantees this benefit. CO not only does not guarantee it, but you have a player with this advantage still in the hand when you enter the pot. Playing against an aggressive player who understands the value of his position (BTN) degrades the value of your (relative) position (CO), since s/he will basically nullify your perceived advantage (being the effective BTN when the real BTN folds).
Against a non-aggressive, non-positionally aware player, the BTN's advantage is less, since the BTN will fold middling hands that ought to be played based on position, giving you the effective BTN more often.
And when you're calling from the CO, you're vulnerable not only to being OOP after the flop, but also to 3bets and being outplayed postflop by the BTN, who can act after the PFR and caller (you), which is a huge advantage.