Would be great to see a benchmark of how much time is actually spent in routing compared to all the other disciplines involved in responding to a HTTP request. For any interesting application, I suspect routing will be the least of your troubles in regards to performance.
For most web-apps this is definitely true. But an efficient router doesn't hurt either.
If the router scales well, the routing part will never become your bottleneck. If the router is also memory efficient, it can reduce the amount of time the Garbage Collector needs.
