I believe it is, very much so. A 10" prop spinning 16,000 RPM needs it just as much as an 18" prop spinning 9,000. Vibration weakens airframes and quite possibly electrical components. I balance every prop before I put in in my flight box. Takes maybe three minutes, some twice that. I scrape the face of the heavy side with a #11 blade and then buff it with 400 grit - and also take the sandpaper lightly to the knife-like trailing edge of my APC's to round them off. Very rarely do I find a badly balanced prop, but I find many with measurable imbalance.

I love that kind of tinkering during "down" times. Part of why I do this.