About styles of writing FSM

This is down to personal preference. It's highly unlikely that the final implementation will differ as a result of using the different styles. You might argue that a more verbose coding style is more explicit and therefore helps the tools digest your code - there may be some particular inferences that cause the tools difficulty. I don't personally subscribe to this point of view. More relevant (I think) is the comment made regarding a more verbose style - it's more prone to error.