I have 1 work truck with a Leer, 1 with a Century, and my personal truck has a Century. All have been great. My only complaint is that the Leer I have has a push button to open the glass. Very poor design that doesn't work as intended. The cables slip after a year or so and then the class won't shut correctly without constant adjustments. However, this was a returned cap so I got a good deal on it.
When I bought my Century, the owner of the Leer shop said that both Leer and Century are owned by the same corporation and the two plants are directly across the road from each other. After looking at the caps side by side, I can see no difference other than the Century having a round recess for the sticker vs. the triangular recess for the Leer sticker.
I believe my Century was around $100 dollars less than the same Leer.