Yes, compared to those who don't know any Perl, "P5ers" have, on the one hand, a head start (the many identical aspects of P5 and P6) and, on the other, the frustration/confusion that arises from changes including many seemingly
random subtle ones.
Some things to consider:
- I've witnessed (and occasionally participated in) continual discussion over the years of established aspects of Perl, from the spelling of keywords and various idiosyncrasies to muscle memory and common P5 mental models, and of minimizing and mitigating the impact of changes between P5 and P6.
- This isn't just theory. Many P6ers are also P5ers and clearly don't like being confused or frustrated when switching between the languages. These P6ers are dogfooding the switching experience and improving it as they go.
- The compiler is helpful. There are many warning and error messages that reflect knowledge of P5isms, their corresponding P6isms, and how to help folk switch.
- Several folk have written P5-to-P6 doc, eg Moritz's P5 to P6 articles. Unfortunately a lot of it is out of date which of course increases the sense of uncertainty. :(
- There are P5 and P6 evalbots on #perl6 and #perl6ers are eager to help anyone wanting to learn P6, including skeptical P5ers. (This is the primary antidote for the previous point.)