The speed of the perl regex engine isn't all that important unless it is too slow for a particular problem you are trying to solve. If the problem is so time sensitive that the perl regex engine is your biggest bottleneck (you did benchmark, right?) then it might be time to rethink your solution. Perhaps moving away from regex, or perhaps using a language built for speed

Where perl shines really is the ease with which you can use regular expressions, and the useful (if monstrous) extensions such as (?{{}}). Using regular expressions in php or c with pcre makes you really appreciate perl. Older java versions were a bit annoying as well, but they have improved greatly in recent years.

Use whatever happens to be the right tool for the job. It won't always be perl, but you can rejoice when it is.