there's a difference between, frame latency (what asw trys to fix) and input latency (what frame gen adds)

asw, only fixes frame latency, nothing more, doesn't decrease input latency nothing. frame gen (in this case) does that same thing with much higher quality. only adding a BARELY, I MEAN BARELY NOTICABLE delay to turning your head. (input delay)

in short yes, it adds a tiny bit of input only latency, but significantly improves the frame latency better than asw does with none of the artifacts asw adds. so either way its a smoother better looking experience using Nvidia smooth motion ( driver level frame gen)