In my mind, the great thing about Perl has always been that it's built into pretty much every UNIX-like system, so you can literally use it out of the box in either Mac OS X or any flavor of Linux. But Perl 6 isn't universal like that (yet?) so to me it just competes with Python and Ruby, both of which I already know and which get the job done just fine, and which I have installed wherever I need it.
I had zero perl experience before diving into perl6. I've found it to be a great language with a fun community.
As for compelling features, there was a good discussion on this a few days ago, so I'm just going to link to that: https://news.ycombinator.com/item?id=10637789