I got my 1301 from CSC, and the mag Tube extension from SJ hardware, just a month ago.
The Beretta is much lighter than the m4. I really like the field stock on it compared to the m4 pistol grip, feels like it shoulders faster, and easier to fit in a pack with less to snag on stuff.
The Beretta eats any and all 12 guage shells I've fed it, with no single hiccups.. Even from brand new. Cycles much better with light loads than the M4 does.
Although price wasn't an issue for me, it is also $1000 cheaper than the m4...
No debate that the Benelli M4 would be the most robust, heavyweight, drop-from-a-helicopter reliable gun you could get for military use with heavy loads of buck and slugs..
For me however, I love the Beretta.. light weight, easy to point, compact to carry, Made in Italy, and eats any cheap ammo I can find for training with it.
And the $1000 difference between the two guns can afford a lot of cheap ammo for training.