I've heard mixed things about the dynabeads...seem to remember reading an article that put a wheel on a balancing machine, noting the results, then adding dynabeads and running it again, it produced the exact same results, it wasn't magically balanced.
I have personally done this & noticed no diffrence with Dyna Beads. I personally wont waste my money on them. I never balance my back tires & the way the tires are made now they have more overlap & they dont take near as much to balance. Unless your gonna run 200 MPH you could line up the balance dot & prob never notice any thing with out balancing. I have done numerous wheels on a spin balancer that requires no weight except for Harley wheels they dont seem to be balanced real well.