How do you like the surface? Would love to know since you are quite familiar with macs and the OSX experience.
I like the Surface Pro a lot, although let me make it clear that it's not for everyone. The mistake that people make is that they try to group this device with a tablet or an Ultrabook. It's neither so of course it will fall short in both categories. It's in a league of its own. If you are looking for a just a notebook, the MacBook Air is the way to go. If you are looking for just a tablet, then the iPad Air or Nexus 7 is what you should get.
I travel a lot for work and my company relies on Outlook (for Exchange) and Excel a lot. No matter what anyone says, Outlook 2011 is still not up to par with it's Windows counterpart and the same can be said about Excel. Having to run Parallels or boot into Windows through Bootcamp is not ideal since it shortens the battery drastically.
On some trips, I try to travel as light as possible and taking the iPad Air with the Logitech Ultrathin Keyboard would be the perfect solution, however the Safari mobile browser is very limiting on some websites and there is quite a bit of compromise on productivity apps. The iPad Air would be great to take on vacation if I wanted to look at email, social media, etc. Speaking of traveling, the cool thing about taking the Surface Pro on trips is that you don't have to take it out of your bag through TSA screening since it's considered to be a tablet so it saves some time.
Now that I have the Surface Pro, I've been using my MacBook Air less and less and have been leaving the iPad Air at home to just read in bed and I just take the Surface on the go. With Dropbox or SkyDrive, all my work follows me no matter what system I'm on anyway. I know some people may not believe this but Internet Explorer has come a long way. IE 11 is a joy to use and I like it a lot better than Safari and Chrome. Safari on the iPad Air in iOS7 crashes a lot. Chrome has been a clusterf_k lately as well on the Mac (not sure how it is on the PC).
Hope that answers your question!