Rob,
Just a little side note about the WOT db test. I'm from NJ and they did away with that a number of years ago because they didn't want to be responsible for having you operate your boat at full throttle. Since most offending boats are probably faster than average , suppose someone had a mishap or broke something like a $25,000 engine at 80mph or better? Laywers would be circling like fresh water sharks

.
I'm like you Rob, I have 41 hours on the engines so far this year and most is 3000 rpms or less.This still will get me 50 mph. Wide open throttle time is probably less than 10 minutes.
LRSLA,
Those noise figures you gave for your boat DO seem a wee bit high
Remember " People in glass house shouldn't throw stones".
As for stress , being back home now , yesterday I made a 104 mile (round trip) lunch run. Total running time about 2 hours and 50 minutes including NWZ's. Riding in something that weighed probably 8000 (including 130 gallons of gas and 5 passengers) I personally felt great!