Mid-length gas systems seem to be the norm, but carbine gas still chugs away, even with cheap ammo. My beat-up AR with a carbine system eats anything I feed it. It's tough to argue with that kind of won't quit kinda thing.
For me, a mid-length gas system just feels smoother on a sixteen-inch rifle. You get less snap, less wear and tear and usually just less drama with the tuning. A carbine length still works perfectly fine though especially if someone's looking for absolute reliability even with weaker ammo or cheaper parts.
A buddy let me run his mid-length beside my old carbine during a long range day and by sunset my shoulder already knew which rifle I’d rather carry again.