I don’t like them...but are a must have if you have grades
I converted about 5 or 6 of my Railking diesels...a good freind got me a coffee can full of wheels from a man that did 2 rail conversions. I have no grades on my small layout so I replaced the grooved wheels with regular wheels.
I also found a use for the grooved wheels on the FM trucks I got rid of the blind axle wheels and replaced them with the grooved wheels it looks a lot better but the locomotive has to only be used on wide radius track.
Before
after
Heres a short video of the locomotive pulling a PWC train