Sorry I'm getting back to you so late. The only time I had to adjust the Sinn was any time I took it off more than 42 hrs or so. It hasn't been too fast or slow. As for the dehumidifying capsule on the side..from what I heard turns blue when when water is detected and yes it's covered by some kind of glass. Luckily mine is still a whitish color. I got the watch for $1700 back in March. The 656 measures about 38.5mm...the 856 measures 40mm..not much difference in size. I liked the 856 due to the Tegimenting Process makes it hard to scratch. I banged it many times against the table, car door, the aluminum trim in my e90, and still no scratches. No matter which one you pick it'll be a watch not many people have. Hove this helps...Sorry I took too long. Think I'll start readiing my personal mesages.