I am speaking as a relative newcomer to Perl. So with all respect I can say that I have used BBEdit to do a "Find and Replace" on over 100 files in multiple directories. It is fast (~5 files a second), accurate on changes to a small number of characters (15-20 charaters at a time), and will provide a summary of changes as well as automatically save or allow you to manually save.

By the way, I have no conection to BBEdit in any shape or form.