I think this is where Ruby's reputation for being slow is a bit misleading. Perl is faster because it doesn't have OOP baked-in. Pre-load Moose and Perl's performance isn't that different than Ruby's.
Honestly, I don't know, but I would assume Ruby's OO performance is better than Perl's with a very large extension (Moose), where some optimizations just aren't possible, given the core architecture of Perl, but I'm really getting above my pay grade in what I know about Perl internals (which is almost nothing, really, that's some scary looking stuff in there!).
I do look forward to the new class system coming to Perl based on Corrina, but I also can't comment on how performant it's going to be, either. My guess is that going ahead on this large project was based on answers to questions like, "is it going to be more useful than Moose?" "More performant?" Because if not, why not just use Moose?