They might be a bit agricultural compared to a Yamaha, but that said they're absolutely bullet-proof. Only weak point I'm aware of is the remote cable isn't tinned, so any electrical issues can normally be traced to a break in connection. A simple continuity test will identify. Parts back-up is great and on a par with Yamaha in my opinion.
The Yamaha 3 cylinder 50G are great engines too and were used pretty extensively by commercial fishermen, which is part of the trouble as they're almost impossible to source. I waited 2 years to get carbs for a Yamaha 40V (same block) and gave up in the end.
Buy the Tohatsu and you're joining a pretty exclusive club.