The problem with the Simplex locks is the chamber. When the chamber is on the outside of the door it is susceptible to rare-earth magnet attacks. The models that have the chamber on the outside of the door are the ones where the five buttons are in a straight line. The models where the numbers are in a circle have the combination chamber on the inside of the door and are immune to that kind of attack.
(It does have a week point, but I still use this type.)
If you are getting the 14 button lock my suggestion to you would be to buy two (either for you and a friend or for a front and back door). Of the 14 buttons, one is to clear the combination, 5 are for the combination and 8 are wrong numbers.
Since 5 are supposed to be in the combination, if you trade one of the “combination” pieces from one lock with a “wrong number” piece from the other lock, one lock will have six numbers in the combination while the other one had four. This will throw off anyone trying to break in. I don’t know anything about the strength of the lock itself, I never break locks to gain access.