[quote name='Koopler']So Round1/2 are better than the "S" models?[/QUOTE]Parts wise, the Round 1/2 and "S" models have 100% the same parts, which is truly the most important thing. As for the comfort level of the stick, some players prefer the smoother corners of the Round 1/2 model. Still, some players couldn't care less about the sharp corners of the "S" model and it doesn't really bother them. Personally, if I really really had to choose, I personally would buy Round 1/2 models because they are usually cheaper and they have the smoother corners.
[quote name='shrike4242']Any mechanical differences between the Round 2 and "S" models?[/QUOTE]There is a very tiny mechanical difference between the Round 1/2 models and the "S" models. That difference is in the "lock" button located on the upper-left hand corner of the stick (it's that upper left black panel that you use to control the turbo functionality of the controller). In the Round1/2 sticks, the lock button does not lock the start and select buttons, while the model "S" does lock the start and select button. In the end, this actually doesn't matter, because the start and select buttons are located in a very conspicuous space that should prevent any accidental pauses.