Yeah interesting, I had never done much research into it but it looks like the pipe (random hwy dude in question did have a pipe) and a power commander ECU does exactly that, moves it from a 55 top speed to a 70 top speed. Most honda I've worked on adding a pipe does nothing so I assumed it was irrelevant.
I would still say almost all the motorcycling I do, I could do at 60 quite comfortable, but then again most of my mopeds do about 50 and I have them to ride when I want to putz around in town.