It depends on your style...as was pointed out by jahmez, if you want to fight like Tyson and use the crouch then you will be easier to reach, easier to hit, and you'll have difficulty vs someone that can move. If you have a more upright style you're going to sacrifice some of the speed in which you can throw combinations, you're going to sacrifice time when you're throwing punches, and to use height effectively you have to be VERY active with the jab and the cross and you must beware of counterpunches.

I think there are pros and cons to both, the main idea is that you use what puts yourself in a better position to win rounds. It's never a bad idea to at least LEARN both styles...I always tried to merge the way Tyson fought and the way Lennox Lewis/The Klitschko's fought in my mind when I fought. If I was in close quarters I could slip a punch rip off a combo and tie up(Mike Tyson)...if I needed to keep someone off of me I would use the 1-2, hook out and circle (Lewis/Klitschko's). I wanted to use the best of both worlds when I sparred anyone and once I start going back to the gym agin I'm going to try and add more defense and counter punching in the mix ( I never really focused on it until now).