Also, perl 6 is effectively a completely different language from 'normal' perl (i.e. perl 5.x). The difference between the two is far far bigger than say python 2 -> 3.
As a perl programmer, I see no obvious benefit from switching from perl 5 -> 6, it would be the same as switching from perl to a completely different language. You're not going to be able to take your existing code and familiar libraries with you.
To be clear, Inline::Perl5 (and the other inlines like Inline::Python) automatically marshal data.
And exceptions. And classes (so you can sub-class a Perl 5 or Python etc. class in Perl 6). Etc.
The project has mostly stalled since Inline::Perl5 became so effective. v5 had the issue of being unable to easily support binary XS type modules. Which means it could never support CPAN, unlike Inline::Perl5. It was meant for people to be able to copy their high mental cost algo code into a new Perl 6 project without fuss.
It has signature, and subsignature parsing, built-in concurrency, not to mention over a dozen other features that are not in Perl 5. The main reason it is called Perl 6 is how the project began. It started out as Perl 5 minus a few warts.
As someone who well versed in both, they are very similar, and very different at the same time.
I like to categorize the differences like this:
Perl 4 is to C, as Perl 5 is to C++, as Perl 6 is to Haskell,Scheme,C#,D,Go,BNF...
That is Perl 6 brings in features from many diverse programming languages, and combines them in such a way that it feels like they have always belonged together.