I can’t imagine anyone being bothered by AR-15 recoil.
It is almost not even noticeable and I have never liked recoil.
I appreciate your perspective, but ...
My friend was in his most recent firefight ~11(?) days ago.
i.e., he was there, on duty when the bad guys blew a hole in the wall with a truck bomb and the squirters ran in wearing US Army uniforms.
He was in Desert Storm I and II, in Baghdad for the handover, and now Afghanistan, multiple tours.
He STRONGLY recommended getting the recoil reducer, especially if you are using optics, as you can REALLY keep the aim point on target when firing multiple shots, fast.
I’ll go with his recommendation. That’s just me.
Yes, but Burst Fire or Full Auto with a M4 is a little different matter.