The Macbook Pro Retina model may not be an ultrabook by heart but it is slimmer than the rest of the Macbook line up, except the Macbook Air, of course. The Retina model is a paradigm shift. You should only buy this only if you are ready to embrace the future of display technology. Apple has taken a huge leap with the retina display and apps look better than they used to.
The 2012 version of Apple Macbook Air is still one of the thinnest and lightest ultrabooks around. It is also the only ultrabook to choose if you want one loaded with Mac OS X operating system since Apple does not licenses its OS to any one else. The new version adds features like USB 3.0 ports and the new Intel Ivy Bridge processors.