From what I've heard and read, Cubans, in general, seem to have a more predictable temperament. Everytime I have heard an anecdote about a bad bite from a Cyclura it has been a male rhino. Now, that said, every animal has it's own individual personality and you could get the world's sweetest rhino or the world's most temperamental Cuban. So as JF said, it's best to go with what you like.