I have Original Windows 8 on two laptops, pre-installed from factory, working flawless! I love it and prefer it over windows 7 any day because of the apps. Windows 7 is based on the same design as all the previous windows like XP, 2000, 98 etc. Windows 8 is a complete redesign of windows OS.
My laptop's battery lasts for over 6 hours while a similar laptop with my friend, HP probook 4530s 2nd Gen i5 dies in maximum 3.5 hours. Just browsing, pakwheels, facebook, email and sometimes if I watch a TV series episode, battery life decreases by 10-15 minutes.