I purchased a new car in May of 2000 and picked up a nail in one of the rear tires about 1500 miles later. I pulled into a nearby tire shop and they patched the tire from the inside in a matter of minutes and didn't even charge me for it! I've still never figured out why, other than the guys were having a very slow day and were super friendly - I just don't get that sort of luck!

Anyway................ never had a balance problem, never leaked air, never an issue of any kind. Got rid of the car 4 years later with just over 50,000 miles on it. And the original tires - including the one with the patch.