The starting question comes up, regularly. Often the OP has already read old cruising books with strong opinions by authors with (sometimes...) actual good experience.
(sigh...)
Those authors sometimes do not acknowledge how much of their survival was due to chance and luck.
Thing is, there are unwarranted assumptions in even the underlying basic details.
Construction never seems to get its due. (!!)
For instance, a fair number of skeg rudders have a design weakness in the skeg itself, and some simply break off in big seas. Some spade rudders are poorly designed both with regard to the shaft and support, and/or the inside tube where it is glassed into place. The lower gudgeon on keel-attached rudders is a hidden wear/failure point, and may or may not have been well-designed to start with.
As for pot warps, tucking the prop up behind a keel or inside an aperture does make it more difficult to suck in a line. "Difficult" is not the same as "inconceivable" to borrow a great movie reference. (I have experienced a crab pot line snarl at sea with the prop up close behind a fin keel.)
A fin keel is only as strong as the casting and bolting and inside framing. Build quality and engineering is very very important. That's why the cheaper-end 'party-time interior' production boats are riskier for sustained time at sea.
Note that any boat will depend, to some extent on both luck and planning to avoid dangerous sea states. The built in quality just moves the survivability needle further towards the 'life' side of the dial for us.
Remember, that with luck you can get to Tahiti and be sipping a cold French beer in your cockpit, like that young guy written up in a Cruising World article in the late 70's.... with his Nat. Geographic map for navigation, in his Catalina 27.
Most of us did adventuresome (and sometimes stupid) things when young, and most of us survived to lurk on the internet in our golden years..... except those that died in a rice paddy.... which I avoided with the luck of being assigned somewhere NOT 'in country'.
Luck... is a good thing!
But, please... just stop obsessing about type of keep or rudder. After getting opinions from total strangers on the 'net, start talking to surveyors about boat quality. Pay them for their time and expertise; it's worth your life.
Take notes.
ps: both the Niagara and CD are strong-enough boats, but I prefer the hull-to-deck joint construction on the Hinterhoeller boat. I owned a smaller Niagara for a decade and sailed it hard.