mbstring vs iconv benchmarking

Following up on my previous post about the differences between the mbstring and iconv international characters libraries (which resulted in a tentative conclusion that nobody knew anything about those differences), and particularly the comments by Nicola, we have combined forces (mostly efforts from Nicola, actually) to provide you with a little benchmarking, if that can help you decide. Nicola wrote the following script (which he gladly releases as public domain license) to test th