I've not had first hand experience doing these valves, but from what everyone says, they stay really consistent for thousands of miles.
In the old Honda days, I adjusted my own valves approx. every 2,000 miles. Back then it was a piece of cake. 4 valve covers, small wrenches and feeler gages.
It is better that they loosen over time rather than get tighter.
Honda seems to have hit a home run here with these engines.
"The difference between death and taxes is that death doesn't change every time congress meets." - Will Rogers