Hello!
Yes there was an update to the S340 which added a couple of things better for the user but the window is basically the same as the previous S340. What I would recommend is that if it gets dusty, use a can of compressed air which usually gets the work done. I know some people get these if they really want a better window http://mnpctech.com/nzxt-h440-s340-razer-replacement-custom-window-smoked-clear-red-uv-green-blue/clear-replacement-cnc-machined-window-for-nzxt-h440-cases-clone.html
If there are any other questions, you can always PM me.