"With all of the changes mentioned above the overall processing time per packet for small packet routing is reduced by over 100ns per packet."
Right. This is for the case where the machine isn't doing anything with the packet except sending it back out. But it might also help when the machine is performing a service which requires very little CPU time but moves huge amounts of data. Like serving video. Are the big video servers still x86 machines, or does Netflix now use custom hardware?
If it's a web server constructing pages on the fly from a database, that work will dominate the time spent getting the packets in and out of the machine.