I think a Shannon 38 is a more fair comparison. The Shannon 39 is a bit more modern in that it's a fin
keel with a skeg hung
rudder. So the Shannon 39 will likely out-perform the
Cabo Rico 38 in pointing, light air, and close quarters maneuvering. From an aesthetics point of view, I've never been fond of the spartan looking below decks accommodations on Shannon's. It is the
classic Herreshoff style with lots of clean white surfaces and trimmed in hardwood, usually
teak.
Cabo Rico, in later years, also offered interiors tending toward the same style. This was an option that would lower the final
price of the yacht. Some prefer that look, but I don't. I'll keep my
teak forest. I find the interiors of Cabo Ricos simply stunning. But that is truly just personal preference.
From a construction quality standpoint, I've found my CR to be well built, but all old boats require some updating/refit. There are a few things which could have been done better, but they are addressable without too much pain. I've not had the opportunity to closely inspect a Shannon, but my understanding is they are very well done. I've found Cabo Rico's to sail well and to handle themselves very well in snotty conditions. They're comfortable and have good tankage. The
tanks in older boats may need some
work, but the benefit of
fiberglass tanks is that they may be worked on in place if necessary.
At the end of the day, I think these two boats are pretty comparable. I'd pick the one that makes your heart go pitter-patter.