Vibrations do get a lot less with age, and keeping the heavy bar-ends does make a difference.

Personally I can cruise at 5.5-6k rpm and hardly notice the vibration (13k miles on the clock however). I used to get a load of extra vibes around 4k rpm but that went by about 4,000 miles. Seemed to smooth out again arount 9,000 miles.

I'd say wind buffeting is far more an issue, and then only really at high speeds (for me anyway)