Yes - its wonderfully formulaic - the detective's sudden vision, based on some random thing said by somebody, the explanation of the crime and then the way they invariably confess or breakdown in tears, ending it all nice and tidily.
I think its fine - a nice escape to a sunny place, a plot that's easy to follow without having to think too much. The quality of the acting is irrelevant really - its all pretty lame, but who cares? Having lived on a similar Caribbean island for several years in the 90s/00s it takes me back too.