I am interested in purchasing a watch and I happened across the Sinn 256. I know this watch is based off the 156 model but is smaller and has the valjoux instead of lemania movement. Those of you who own the 256 or have interacted with one, what are your thoughts on the watch as in durability and wear/tear for an everyday wear watch? Also, I was curious to know whether I could get this watch with a saphirre crystal glass instead of the acrylic glass they provide? Any help that you might be able to provide would be greatly appreciated. Thanks.