I would suggest that you not even think about Windows 8 unless you get a touch screen. └lthough it is much faster and will improve performance on most hardware, unless you are running it on a touch screen device, the new interface will most likely be extremely frustrating.
If you do want a touch interface, I would definitely recommend the Lenovo yoga 14 which I love. It has all the bells and whistles, weighs only 3.5 lbs and can be used as an ultrabook laptop, tablet or tented display. For the light weight, you give up a DVD drive, but you do get a very responsive touch screen, Bluetooth, HDMI and almost instant startup.