You may want to check yourself cody.
The M1/M2 series do not perform reliably once accessories are added to them... such as; light, extended mag, optics, side saddle, etc. Due to their design, additional weight (more than a single accessory) may cause them to cycle unreliably. Period
M4 will cycle with multiple accessories, additional weight does not affect this weapon as it does the M1/M2. Period
If someone anticipates adding one (single) accessory to their Benneli then the M1/M2 will work for them. As soon someone anticipates adding two or more accessories then the more reliable platform would be the M4. End of story.
I own both.