my best advice for this would be to explain what each is because I don't have anything to go on.
Fast: getting rid of unnecessary word and/or phrases to make the sentence shorter and more to the point. or given tons of information all at once thus giving the reader a rush.
slow: moving the plot along slowly, stringing you along to keep you interested but annoyed to keep you hooked.
suspenseful: this is giving key words leading you on to what you think might happen to keep you guessing so you keep reading.
Explanation:
sorry is this doesn't help, I need sentences to be more specific.
