I finally put Win10 on my SP3, build 9926. I'm flabbergasted at how much I don't like it so far, but it's a preview so I will hold out hope. One thing I'm VERY much missing are the quick brightness/volume sliders which used to be on the charms screen, they are nowhere to be found. The automatic brightness setting is garbage and I've never used it, preferring to quickly slide the brightness up or down from the charms bar. Now the display button in the notification pane simply brings you to display settings. You have to drill down quite a bit to find the brightness slider. Not that it's a solution, but even the keyboard function controls don't work to control brightness, although even if they did it would do nothing in tablet mode. Anyone have a solution, reg hack, tweak or at least acknowledgement from MS that they will reimplement this?