Hi all, I am about to purchase my FIRST ever Mac. I have zero issues with Windows based PC's other than notebooks have terrible battery life. This is the main and only reason at this time I'm looking at the Macbook Pro/Airs. Anyways, the main use is for work, we use excel spreadsheets quite extensively and I wanted to know how Office for Mac 2011 ran on a fully loaded 2011 Macbook Air (Upgraded CPU and Memory) Also I wanted to know from someone with first hand experience is there is anything that I may have issues with opening/editing/saving .xlsx files when using them between PC's and my new Mac? They were all created with Office 2007 for Windows. Thanks all! I'm excited to try the Mac, been curious for a while.