Thanks for sharing! My perspective is of course as a user. I don't think I've ever run into a case where the compiler broken a previous work e.g. C++ program. On the other hand I have to make a release of most of the libraries I maintain with every GHC release (to bump cabal version constraints to accept the new base version, if nothing else).
gcc has had its moments occasionally, although usually major gcc issues aren't called by gcc itself but by packagers ("gcc 2.96", anyone?) or fugly politics (egcs).