What's the difference between the Benelli M2 and the Montefeltro?
The M2 has a fancy stock with additional recoil reduction features and possibly some differences in the barrel. I have a 12ga Monte and love that gun. I just ordered an M2 to replace a Franchi Affinity 20ga.. The Monte is a basic no frills quality shotgun.
I had the same question and ultimately went with a Montefeltro 20 ga. Below is a link to where I asked a very similar question.
http://oldgobbler.com/Forum/index.php/topic,93041.msg910087.html#msg910087