I have 4k+ miles on the full Stoptech bbk and have had no vibration issues. Several hundred of those miles have involved hard brakeing in the mountains. The car is not driven competatively however. I have been very pleased with the f/r balance of the stoptech kit and would never do a front brake upgrade without taking steps to balance the rear (could be just through a pad change). For my purposes maintaining nuetral handling under brakeing is more important than peak brakeing force. If cost is a factor, there are a number of very elegant 2-piece rotor upgrades that leverage the relatively nice factory calipers.