Thanks for your editorialized title, but you're overhyping. In my Mathematics::Combinatorics::Combinator, the memory/speed trade off was one of those lifetime-of-the-universe sort of time differences. The CPU/Memory speed ratio isn't likely to ever get that big. Hence, the memory/speed trick will always be useful tool.
in reply to STOP Trading Memory for Speed
It is almost assuredly less work for you to write your own memory management than for Perl to change whatever you feel is necessary to fix your problem. If you want more control and speed, use C. And who knows what will happen with Perl 6 anyway.