Actually, Beav, Martin at the time of the signing is two years older than McCann was when he signed. Hence, he'll be two years older than McCann will be when their deals expire. And, as you say, McCann is a much better player, over 50 points of OPS higher over his career, not to mention more durable. Martin, however, is the better defender, though not enough better to offset the offensive difference between the two.The Jays are paying Martin almost what the Yankees are paying McCann for a catcher who is a year older and not as good a player.
Still, I wouldn't call it a bad contract.