I can pop the front door lock in less that 2 seconds. (I learned from the scumbag who tried to steal mine). Most thieves don't know much about different models of cars but do know that convertible soft tops are easy to slice open. I've heard stories of people who don't even lock their doors and still get their top cut. When I daily drove my Jeep I removed the front door locks and installed electric. I also kept a padlock on my swing out tire carried to protect the back. After I did this I didn't have anymore attempts to break in to my Jeep with the hartop installed.
Plus the zippers are on the outside. If they don't have a box cutter or pocket knife, they can take an extra 5 seconds and unzip the windows.