The tires that I reported needing "Road Force" balancing were a set of new (from Tire Rack) Michelin Pilot Exalto PE2, W-rated tires, in 205/55-ZR16. We can assume that these are high-quality tires -- and I (like you) have a lot of faith in Michelin manufacturing, especially for tires like this.

I chalk up the difficulties I had to sloppy/lazy/inadequately (take your pick) workers at the previous two tire shops (one, an "authorized installer" for Tire Rack, the other another local tire shop). In contrast, the third, and finally successful, balancing (with the Hunter GSP9700) was performed at a local Lexus car dealer -- not to put down Volvo dealers, but Lexus does have a reputation for good service. Perhaps they would have done a good job even with an ordinary machine.

Regards,