I have shot the Benelli M1 and it is a fine shotgun... but I prefer a gas operated auto like the Beretta AL390 for targets and hunting because the gas auto is easier on the shoulder. Gas operated autos spread the recoil impulse out so its more of a push than a punch. The Benelli is recoil operated and the recoil will feel sharper.
The Remington 11-87 is a good shotgun, but in my opinion, the Beretta has a more reliable action and fewer parts that break. For what it's worth, I find I shoot better scores with my Beretta AL-390 than anything else that I've shot, which includes Remington 1100s, Browning A-5, Winchester 101, Browning 425, Benelli M1, & Remington 870s.
For sporting shotgun info, check out the Shotgun Report website at http://www.shotgunreport.com its archives contain a wealth of shotgun knowledge.