My company uses Mojolicious for all our webdev and Perl for all our in-house stack. Full disclosure, it was my decision ;) but the work is so fast and smooth, I can't imagine switching to anything else.

I've been using Dancer/Plack for a number of years now, are there any particular features of Mojolicious which make it preferable to your mind?

Since it is built from the ground up around an event loop, asynchronous requests and responses as well as websockets work much more naturally. With Plack-based frameworks the PSGI spec is not built for asynchronous behavior, so you have to rely on hacks and use specific PSGI servers like Twiggy.