Rod and main bolts-replace?

There are two schools of thought out there. One says ALWAYS replace your main and rod bolts with new during a teardown. Seems obvious. The other, less-often heard school says if they look OK, they're already pre-stretched and have proven their integrity by not failing. Most bolt failures occur in fresh engines with new (read; defective) bolts. Any thoughts on this from the racing crowd? (who tear motors down quite frequently)