Benelli M4 is an excellent shotgun. If for HD it is heavy and not conducive to CQB but a heck of a choice if you are wise enough to post up with cover in a room and await the bad guy coming to you. All around one of the best, most reliable shotguns out there. I have a collapsible stock but prefer Mesa Tactical pistol grip over OE Benelli which is an inch LOP longer. They shoot heavy slugs and Buck to lightweight birdshot without a flinch. Be prepared to open the purse for extras....
I have a Gen2 and 2.5 1301. Overall, reliability is every bit of the M4. Lighter and easier to maneuver around with by far. Generally, I recommend the 1301 over the M4 for most people, but really can't go wrong with either. Also dependent upon the end use.
Add: I've shot many thousands of rounds down all 3 of the shotguns mentioned above. LE Instructor for over 20 years. The reliability of the M4 as well as 1301 is superb.