Years ago, one of the UK magazines had a dyno day. They asked for any and all GSXR 1000 owners to show up. That meant they had a decent sample size of all the years, and all kinds of different mods. I believe this was in 2008, so they had bike years from 2001-2007, and miles driven was all over the place.
They featured a handful of those tests. Most bike made more power, after a few dyno runs. These were bikes with 5-10,000 miles on them, and even those picked up a few hp after being run hard, like you could do on a dyno.
One in particular had been owned by a older, more conservative rider, and it gained power, on every run, despite already having 7000 miles on it. This bike was never going to be "broken in" with this guy riding it. What you could see is these powerful engines never work hard under normal, legal riding conditions. You get to use full power on very few occasions. Even then its for such a limited time