When you say reliably I assume you mean every time and in any weather? I may have to look into getting one myself.
Yep, but then I don't get -40 here in FL, but with the right loads for the temps, I have no doubt about it - if a goose gas gun will let me shoot 28 gauge payloads without failure to feed or eject, I consider that a good gun
I don't know much about the different systems of operation (I mean I understand them in principle, but not in specific differences in practice). Can someone help describe the advantages and disadvantages of each system?
There are three main types - gas, long recoil, and inertia. With a few exceptions, the majority are either gas or inertia. A gas gun utilizes some of the gas generated by firing to operate the action of ejection and reloading. This makes it softer shooting because by doing that, it lengthens the recoil pulse so it seems to be more of a gentle push than a hard shove. For the most part they can handle light to heavy loads without major issues. Downsides - if the ports get clogged, operation can start to be hampered by jamming, failure to feed, etc. Cleaning a gas gun can take a little longer than an inertia gun.
An inertia gun, like a Benelli, basically acts like a blowback pistol utilizing the forces generated to move the bolt back against a very stiff spring. Since all the gas goes out the barrel, cleaning is somewhat easier than a gas gun, but the downside is that the felt recoil is more and the gun may not like to shoot light loads or target loads below 1-1/8oz, 1200 fps. Because there is no gas action up front, the gun is lighter which also transmit more actual recoil.
There are two recoils to be dealt with - actual and felt - felt is also known as perceived and "kick"
Actual recoil is a simple math equation involving the mass of the payload, its velocity and the weight of the gun
Felt recoil is what you seem to feel via fit, the gas action spreading the pulse out, etc.
I'll let RC or someone else discuss long-recoil, ala Franchi and Browning old semis