Originally Posted by DLSJ5
I would add that if the supercharger is tuned correctly, running at the proper psi and running the proper octane, a failure is very unlikely as well.
+1 Given proper tuning, boost, and running an adequate octane rating a supercharged engine should be plenty reliable and a catastrophic failure should be highly unlikely.
A boosted engine most likely won't last quite as long as an engine running stock power levels, however, longevity will still be quite good and most likely in the hundreds of thousands of miles before needing a rebuild. This of course is providing that the maintenance intervals are adjusted to reflect the additional power levels!