After re-reading your original question, now I see what you were getting at. Sorry about that.
For me personally, it would be a no brainer. I would opt for the MacBook Air. I'm a Mac only guy and have always been a Mac only guy. My limited experience with PC's was when my daughter attended Cyberschool and the laptop that they issued their students were Dell computers. She used this laptop for two years and while it served its purpose, I was never wild about the Windows OS. To be fair about it, I had never used a PC before and haven't used one since, so my experience is very limited with Windows.
For me, the big drawback with all of the newest Mac computers is the lack of an optical drive. I know that the computing world is going to the cloud, but not every person that uses a computer has constant Internet access and even those that do may not have the fastest download speed around and that makes having to rely on downloading software for your computer a real pain. On top of that, if you have a collection of movies or videos on DVD, that excludes the MBA - unless you want to buy an external optical drive to lug around with it - and that sort of defeats the purpose of having the light, portable computer in the first place.
In closing, like I said earlier, only you can decide what will work best for you, but once again, based on what you are saying... and as much as it pains me to say it, I would go with the far less costly PC. Based on what you want to use the laptop for, the $800.00 difference is probably hard to justify for a MBA.