I run a 40hp tiller on my commercial skiff, tons of hours, thousands of shifts, lighter in weight to other 4 strokes, and all servicable parts/filters are out in the open so you don't have to take the cowlings off, I'm on my second one, and won't run anything else. I have most of the commercial guys around here switched to, or about to when theirs are ready for replacement, from 40 to 150's, absolutely no complaints, very few service issues, look at any pictures of boats, marinas, in Alaska and see what motors they run.
I think their warrantee is now 5 years for rec's, I'm surprised the merc you looked at was more money, usually the Hondas are a little more then other brands.
Like any 4 stroke, do the regular oil changes, put a Racor fuel filter/water separator on the boat and use a ethanol treatment in the gas, I treat every gallon that goes through my motor with the blue Stabil, run it like a normal human being and it will last. Any questions let me know, good luck.
