I think its easier to get the newer opti on wrong than the older style.
My 94 will only go on one way unless you hulk out on it and force it, which we all know is not the way to install the opti.
My 94 you just line up the splines and you know when its on right, you can feel it.
Now it seems to me the newer style has three holes the pin will fit in and only one is the right one, so it would be way easier to get it wrong.

Ever since I did the new opti on my 94 I have been wondering why GM changed the drive mechanism, it seems the older style is a better design to me, now the vent is worth it but the drive mechanism just seems worse to me than the 92 to 94s.