Side by sides have nothing to litigate recoil, you squeeze the trigger and everything gets transferred through the stock to your shoulder.

With a gas-operated semi, the gas system is siphoning energy from the discharging of a round to cycle the action absorbing a fair bit of recoil.

Upsides to a sxs: simple, always goes boom, easier to figure out if it doesn’t one day. Downsides: 2 shots per reload, full recoil baby!

Upsides to a semi: fires as fast as you can squeeze, absorbs some recoil, I can’t stress enough how fun it is to put 6rnds down the pipe before the first shell hits the ground.

Downsides to semis: some are picky about ammo, gas-operated ones tend to get sluggish in the cold, way more complex overall.