Last year, my entry for level0 of stripe3 was a tiny perl script with no tricks (http://pastebin.com/XLZmmPX7).

Using perl, you can not win speed benchmarks, but a C program significantly faster than the "normal" perl program, needs much much more development time.

I have already encountered a C project that was rewritten in perl because it was a maintenance nightmare. The client was very surprised by the performance increase.

I do not know what are your "commonly-occuring" tasks, but in my experience, perl performance was never the bottleneck.