RE: Ocean Alexander
I had an Ocean Alex 42' Sedan about 10 years ago and loved it. (Still do) Not knowing what my "mission" was going to be, I sold it to try something else. I have had 8 boats, all sizes, since 1995 and to this day my wife says the Ocean Alex was the best! Certainly not a trawler, the Ocean Alex was equipped with Cat 3208's and would cruise at 20 knots.
The boat that replaced her was a 38' Sport Fisher (Also a 20 kt. boat) that had the Cummins 5.9 210hp engines. they were much easier to service (belt changes, oil changes, etc) and never gave me a moments worry. Since 1995 I've owned a total of 4- 5.9's in various horsepower and I love them. My current engine is a Cummins 330B (Also a 5.9)
Although I believe there are numerous good to great engines out there, your question was specifically aimed at the Cummins 5.9. IMO, you can't go wrong!