Never heard of it, but then I'm using a version of SVR from October 2018 so it probably isn't available to me. I wouldn't use it though. Smoothing would make the motion I see slightly out of sync with actual head movements, and that's a major contributing factor to motion sickness.
Well, I've never had any of the issues described in those posts, so I guess I don't need it. Sounds like one of those thing you try if you have problems, or leave alone if you don't.
It was turned on by default for my Index, I didn't notice anything negative about it. But I'll test without it, because now you made me curious.
I'm not using the motion smoothing in SteamVR but i'm using ASW with my Rift. It does have some visual artifacts, but it's still way better than stuttery 45 fps without it when my system isn't fast enough for stable 90 fps. And i can use lots of supersampling in most vr games which increases the visual clarity a lot.
I'm using Only motionvector on the HP reverb and its Great. Steam VR got a update recently any 1 else Notice that RRE will Not load up if Afterburner is running Now.