Another ride and a fill up today. 3.1 L / 100 km. Lots of highway and full throttle to keep up with traffic. I'm thinking that's pretty good and it will probably get even better with more riding, especially since I seem to be flogging it a little less to keep up recently. Top speed with a tuck and not drafting anyone is 110 km/hr. It seems to be able to cruise in 6th gear some of the time now which wasn't the case before.
The Honda dealer has ordered me a 14T sprocket for under $17 tax in and I ordered EBC heavy duty clutch springs from ebay. When they come, I'll have a look at what's in the oil screen and another change of synthetic oil.
My personal experience with air filter / exhaust mods is spending lots of money for more noise and maybe a little (or maybe not) more power.