Finally, most of us, have single core or a few core computers. On machines like these, parallel processing is usually just an exercise in coding, and dosn't really speed anything up.

Surely this depends on the task?

Parallel::ForkManager has long given the simple example of a script to download content from many websites. Here obviously the program is not bound by disk I/O but by network response, and parallelization results in many-fold speed increases. I am using MCE for similar tasks and "dosn't really speed anything up" could not be further from my experience.

I have switched recently from using Parallel::ForkManager to using MCE, mostly because of wanting the extra features MCE provides such as easy shared data structures with MCE::Shared, the fact that the author is very committed to supporting all major Oses, and the fact that the author is very quick to support and help.

Yes, I am a little mindful of the dangers of committing to a "framework", but as brother Discipulus says, we all use frameworks. Some have not been a good choice over my years in this work, but the vast majority of the ones I have chosen to use, after careful research and experimentation, have been reliable and powerful and useful. Perhaps Perl's prioritization of not breaking backwards compatibility is to thank for some of this, as well as the character of Perl developers and the Perl community.

Overall, MCE has been a great choice for me, your basic common-or-garden journeyman Perl developer (I'm not surprised you get different opinions from computer scientists like BrowserUk and zentara).