Thank you, everyone who responded.
Why did I post this poll?
1) Most people will do what most people do.
I am shopping, planning a return to the water after a 30 year break. I was a sailor then. I'm now older, I have changed, my life has changed, my energy, needs and everything else has changed. While I can create mental pictures of what I PLAN to do, its impossible to know what I WILL do.
The Chesapeake is littered with dockside tiki bars everywhere you turn. Speed off on a fast trip for a crabcake lunch (its a Bay thing) and cold beverage? Or will the focus be long trips down the ICW at trawler speeds? Those are very, very different needs.
So I was curious about what most people do. How they push the boat or kick back and chill. What I'm seeing is not a bell-shaped curve of a normal distribution, but rather a bar-belled data set. A cluster of pretty low and slow, and another cluster of moving at speed. I will say that as I read responses I noted the boat owned in the signature blocks to the right, and it sure seems like either people bought the right boat for them, or their habits have grown to match the strong suit of the boat they own.
In this case, there is no "most people".
2) Everything in boat design is a tradeoff. To get one positive attribute you pretty much have to sacrifice another. Choose wisely.
There are no perfect boats, only perfect boats for you and your personal mission. Low and slow takes you in one direction, and speed in another. Low fuel burn (operating expenses) takes you in one direction, and time / speed to destination in another. Fun taking in the scenery in one direction, the adrenaline rush of speed in another.
The monkey is still on my back to choose. The mission to optimize for. The big questions are always hardest. And its harder yet for my wife.
3) I've spent evenings this week reading engine performance graphs on a variety of cruising boats. I can be slow but eventually I get it. Yes there are small differences, but one thing is more generally true than not: At speeds that are basically displacement speeds up to say 5 to 7.5 knots (maybe 9, depending on some things) the fuel burns per speeds are pretty much identical across a lot of boats built by a lot of builders, powered by a wide variety of engines.
Above there and the true trawlers start pushing a lot of water and burning a lot of fuel to get the extra turn of speed. And of course they max out since they can't plane. But then speedboat hulls have their own issues at low speeds, burn a lot to get on plane, then things ease up but still burn a lot per mile to keep it on plane. With a speedboat, more engine means more speed. Until they too become unstable with "chine walk".
More engine (than really needed) on a trawler has a marginal impact on performance stats. I've read stats on trawlers weighing 300% the weight of an R31 pushed by 250HP diesels that get identical fuel burn as the RT31. Same big trawler, bigger engine, same fuel burn at given speeds up to about 9 knots. A bigger engine does give more top end room at a massive fuel burn (there, if you need it, but be sure not to need it often).
Read the Penta stats carefully on your own engine, and get it that its producing low HP at low RPM. That's all the HP you need if you are into low and slow. But a smaller low HP engine operating at higher RPM won't necessarily be more fuel efficient for you, only cheaper to buy and less weight to drag around. (Yes, that relationship and statement does break down as you push the edges of the point) Thank you Brian for that lesson over the months. I did read it and listen.
4) Don't buy a speedboat with planing hull if you plan to go low and slow. Don't buy a boat built to go low and slow and expect to change it with more engine. Choose.
Back to my cave now, to contemplate.
