Hello. as one of the guinea pigs on testing windows 10 on sp2...this is what i have experienced... i didn't encounter any major problems (yet) on upgrading my sp2 to windows 10... Performance(updated) - Laggy at first since the graphics driver was not yet installed. after the windows update it works fine. Applications(working) - Photoshop(buggy until graphics was updated),Blender,Zbrush,Visual Studio,etc. Screen Brightness Control(updated) - Not working until the windows update. Sleep(updated) - At first it was gone in the "Choose what the power button does" setting on the power options. after the update it was working fine. no wake ups, no draining. Battery Life(updated) - brightness was max so it drain faster until the updated , after that, no significant change since win 8.1. *update....not as good as 8.1 Power Cover(working) - extra battery works, gestures work on the touch pad(2 finger scroll, 3 finger tap/swipe) Touch Cover(not good) - keyboard and 2 finger scroll works fine but the other settings/gestures are not present in the touch pad settings(probably because its the first generation touch cover) WiFi(working) Heat - no significant change since 8.1. no high CPU/RAM/DISK bursts Pen(working) - didn't have to reinstall the Wacom driver, pressure works, palm rejection improved(only rejects hand side of the screen) *set your handedness on the pen settings Volume Buttons(working) Dock and video-out(working) Storage went from 171gb free to 163gb free space. *haven't deleted the windows.old Method used- since the upgrade app didn't appear on my windows 8.1(since i turn off/manual the updates) i mounted and updated using the Windows 10 ISO file from Microsoft. after the upgrade, the animations where laggy and the sleep and brightness was not working. i let the windows update install the graphics driver. then restart. the lag, sleep and brightness was fixed. then stopped the auto windows update(for now) and changed it to "Defer Upgrades" on Settings>Update and Recovery> Advance options. also enabled the group policy on windows update to notify for download and install. Turn-off a lot of things in the settings(privacy stuff, how updates are delivered, other personal preferences, etc.) Overall experience was fine, i think ill stick with win 10 for I didn't have any problems with windows 10(for now). Everything works just fine but there are some features that i was expecting but did not appear(touch screen gestures), text scaling on some part still blurry, etc.