On our extended Alaska cruises just the extra fuel, food, water, generator, dingy & motor put in an extra 1000 lbs. I agree, a extra person or two without all that, hardly compares & the difference in new more hp motor weight compared to the older heavy less hp motors really isn’t enough weight difference to not go with higher hp, when repowering. To me the benefits of more hp easily out way the little bit of weight difference. In my opinion the only real negative being the extra cost.
When repowering time came for us the several thousand extra dollar cost was eased by knowing all our future boating would be done at a much more quiet lower rpm, which is a very big deal to us. The power if needed a huge benefit too. Where the majority of our time is spent at displacement speed & when on plane 15 to 18 mph is pretty much the optimum for most conditions, increased speed from the additional hp for the occasional time it could be achieved was very low on the consideration for us going up in hp, though I like others, appreciate the ability to do so if needed or desired.
Unlike Boris & many of the old sailors here, I think in & for the most part use miles for speed & distance as boating came late in life & I’m not considering ocean crossing, so see very little need to do otherwise. I also don’t mind doing the small mental conversion jiggling, when others prefer knots.
Jay