Some mClassic Comparisons and Views from Switch, PS3, and Wii.
Impressions are that it does work. Works better when resolution is set at original or closest to it.
Best example is at the beginning of the video. You can see how it will actually look worse when switch is set to 1080p but better when set to 720p. Some games it can change the look too far from the original as in the Cadence of Hyrule comparison.