They are a bit of different animals. The M2 has been my standard clays gun, which also does fine duty in the field. The Cordoba is a 20g (sorry, I didn't mention this last post), which I like to use when our club sets up a "short course" (closer shots) or just if I want to carry lighter shells! The Legacy Sport is a new gun, purchased because it looks a bit sharper than the black plastic M-2. Truth be told, I shoot them all equally well, much better than the other guns I've had (a Browning Citori, AYA #2, Arrieta 871). The only real difference is that the M-2 is a dedicated lefty gun, which makes loading slightly more convenient. I've gotten so used to loading the righty models I wouldn't call it a problem just slightly less convenient.
For whatever reason, I have a tough time getting a good gun fit with most guns. I've tried stock bending, but there's nothing like the ability to custom fit the Benelli stock for drop and cast. It takes 10 minutes or so, and you will have the most comfortable fitting gun you've ever owned.
Good luck,
Ike