The startup time for a script using a ton of Moose classes can be a couple of seconds or even more. Some of my Catalyst applications take upwards of 30 seconds to start (not only Moose but it’s part of the slowness).

A couple of seconds is unbearably long for a command line utility you use a lot and totally irrelevant for a persistent webserver. After everything is setup (all the classes are composed and roles and attributes and all that) it’s decently fast but still something like 5x slower than Mouse for object use (a benchmark). I seriously doubt it can be precompiled sanely. Mouse took a lot of work and has a lot of hands on it and I think no one would have bothered if there were a(n easy) way to make Moose faster.