Not long ago I also installed MOS on my MDD. I also installed the Crysalis pack and it worked well and for me it was a big benefit with a lot of installed programmes and tools. I read that you should only install the right chrysalis version for the right MOS version - otherwise there could be problems. As far as I know there is no ready crysalis pack for the latest MOS or is it?
Also I had no problem with OWB and youtube at the beginning - then after the update to a newer version of MOS with the old chrysalis pack still installed I found out that youtube did not play the videos anymore directly in the window (they seem to start but quickly they stop) but I have to download them. I think it could have to do with the need for updating the scripts I read here - I thought it was the update -> I shuould check it.
So I must say the experience with MOS was quite good. But setting the different screens is a little hassle me thinks...
