Bearings or bushings? (Replacing linear bearings on rods)

[curious aardvark]

I can't see plastic either being as smooth or as long lasting or as accurate as a good set of steel guides with steel bearings.
I can see them being possibly better than a set of cheap steel bearings.

Got to be a video with comparisons somewhere.
Here you go: thomas sanlederer: https://www.youtube.com/watch?v=ZGBipbgwgME