While there is a performance gain Sun's cc and supporting libs often don't play nice with CPAN modules or Perl source install's. Especially on development boxes gcc is the way to go. You may want to point out that the increased code performance isn't going to do much about the usual bottlenecks like io and other connectivity issues

Rebuilding the codebase with Sun's C++ when moving code out of development might be the better solution. This allows the greatest speed to market for the code development via good 'ol reliable gcc, plus saves a fortune on Sun licensing.