This is the origin of the famous quote from Rob Pike which goes something like "Simple data structures are better when n is small and n is almost always small".

This is the origin of the famous quote from Rob Pike which goes something like "Simple data structures are better when n is small and n is almost always small". It hasn't aged as well as he might have liked, given that sometimes n gets really really big now, but the point still holds- in lots of common use cases simple algorithms with low constant factors dominate fancy algorithms with theoretically better O() up to a certain threshold data scale. In this case it would presumably be up to a certain number of routes and/or ip addresses.