Balancing

So I got a set of free continental tires. A buddy has been taking his GTR to a certain tire shop guy for 2 years with no issues so I figured I'd give him a shot. $80 later and done with no scratches and all looked great.... So I jump on the freeway and head home and major shimmy in steering wheel. I go back and the guy rechecks balance and says they are fine, must be the tires.

I started researching the forums and found several threads speaking of a special road balancing machine. So today I headed to the dealership and the consultant said the same thing. I paid $80 and they balanced the tires and now the car is perfect again. How do some get away from using this special balancer? Or is it just my bad luck striking again???