Laravel comes out of the box with a bit more features then Lumen. While Lumen is really for microservices and api's and Laravel more for web applications.
How were you able to get the framework so fast, while still keeping so many great features? This is again due to the great convenience of the Illuminate components. Basically, all I needed to do was “glue” them together in a different way than a full-stack framework would glue them together. This means instead of maximum flexibility in the bootstrapping process, Lumen opts for maximum speed. The actual Lumen framework repository is probably only a dozen files or so. The rest is made up of the Illuminate components. This allowed me to flesh out the features of the framework very quickly, though it did take me three or four iterations to find a solution that was really, really fast while still providing very powerful features.
It's not just the routing. The whole path it takes is much shorter, which is why it's faster. I think the change is a big one and can't be just added into Laravel 5.
It does, someone posted a Blackfire route of a request. Think it's in the popular Lumen thread.
I haven't myself but it uses a lot less code than Laravel. You can't really compare the two because they're so different. It's like a supercar and an off-road vehicle, they do the same thing (drive) but differently.