This just goes to show that you should always check, doublecheck and triplecheck your benchmarks.
Or, perhaps it means that people should limit their use of Benchmark::cmpthese()... they should only compare alternatives that actually have some specific relevance in the context of a given application.
I think you've shown that by trying to isolate a couple of syntactic variants -- stripping away all "confounding factors" -- in order to benchmark their "intrinsic" speed, you end up testing some obscure aspect of the perl interpreter whose impact becomes irrelevant once you put those test cases back into the real world.
