Out of the loop...help

[Unobtanium]

I've been out of the loop for half a decade or so, and I get that this may be an intellectually lazy path vs. scouring this forum etc. but, I had a few questions I hope are easily addressed without all of that. Specifically, as relates to this model:

https://www.benellile.com/shotguns/m4-tactical-shotguns?eid=248

 

1) Has the operating system changed? I mean anything...different piston design, heat treat, spring rates in the piston caps, ANYTHING?

2) Is this rail field strippable pistons and so forth in tact, or are gymnastics required?

3) How is QA/QC at Benelli as of late?

4) I can tell the stock and rail are different from my current Benelli M4, what other differences does this model have, if any?

5) Did they go back to metal trigger guards? That one looks kindof thin, like the metal ones?

 

Thanks!