I've had my eye on the Yoga 2 Pro for several weeks now, and have played with one in the local Best Buy several times. I also own late 2013 13" MBPr, mid 2013 13" MBAir, and 2012 vintage 15" MBPr, in addition to several Windows laptops and the Surface Pro among others.
I would say the Yoga is comparable to the MBPAir, with added touch capability that has some use while in tablet or tent mode.
Your decision really comes down to what you are going to do with the computer everyday. Any of the computers is useful for general word processing, spreadsheets, email, and browsing. So for school or office work they'll get the job done.
Look carefully at the applications you use today or plan to use in the near future to make sure the computer can use them.
I'm not a gamer, so I never pay attention to those details. Just remember that separate graphics controller consumes more power.
What is important to me is keyboard, size, weight, and reliability. Unless you get a lemon, you'd be safe on either OS X or Windows in a general sense.
In my years of using Macs, I've had issues with my 20th Anniversary Mac; 1st gen 15" Aluminum MBP (Apple replaced entire laptop due to display issues); and my late 2013 13" MBPr which had a casing defect near the right side USB port (Apple relaced MBPr due to stress fracture in area within 4 weeks). Apple offered to swap 20th Ann. Mac with G4 Tower and Studio display.
Never had any issues with the Windows laptops purchased in recent years.
So...most of the people here are Mac users, so you will get the typical "Mac is best" response. Go over to the Windows laptop forums and you'll get the PC version of same.
Head on over to
www.anandtech.com for a Yoga 2 Pro review that was posted this week, and look in the archives for the MBAir and MBPr reviews.
Food for thought:
http://lifehacker.com/five-best-ultrabooks-1615183263 MBAir gets honorable mention.
Bottom line, buy what you need and what you like.