"It really is all about parts/
"It really is all about parts/service availability and regular maintenance on the part of the owner.
Honda builds a great engine, so do all of the rest of the major builders.
Within 100 miles of where I live there is 14 Merc dealers almost as many OMC (not a single Tohatsu and haven't seen a Honda either), that means lots of service, parts etc - so I, like alot of others in the area have Merc's hangin' on the back of the boat.
Occassionally a model will come out that is prone to problems, but in the bigger picture that is rather rare (although those are the motors you tend to hear the most about).
Whatever you buy, follow the service schedule. Far more motors end up in the scrap heap because the owner was too lazy to change (or have changed) simple things like the impeller or engine/lower unit oil. The best built motor will fail if it is neglected.
If you can't or are unwilling to learn to do regular service yourself then select a motor that requires less service.
A 4 stroke will need oil changes, tune-up's, impeller changes, valve adjustments, belt adjustments etc - at a shop that could run you a few hundred dollars a year.
The new "direct injected" 2 strokes only require the impeller, lower unit oil and new plugs at the service intervals. But they are often harder on plugs (that go for about 15 bucks a piece).
I guess what I'm getting at is, do alot of homework before you decide what to buy. Answer the questions - can I do the work myself - if not is a choice of shops available - what will it cost a year in maintenance etc..."