I tried using 2011 Excel on my 2013 retina 15" MacBook Pro (2.0GHz, 16GB RAM) and it quickly bogged down and became unusable with a spreadsheet containing 250,000+ rows. I expect in the future I will work with even larger quantities of data and may push up against the Excel limit of a 1 million+ rows. But that is for another day and hopefully 2014 Office for Mac will be out next month. In the meantime, I need to decide on whether to install Windows 8.1 and Office 2013 on my Mac via either Bootcamp, VMWare Fusion 6, or Parallels 9. I need maximum Excel performance. I demoed Parallels 9 and while I didn't get a chance to test drive Excel I wasn't very impressed with how Parallels handled Windows. I*have heard better*about VMWare, and it does appear better from my initial impressions, but again haven't had a chance to try Excel as I don't want to install Office and use my key until I've made a decision (unless I can use the same Office key in VMWare, Parallels and Bootcamp? My understanding is that I am restricted to two installs?) I've read that Bootcamp could perform the best of the three given that Windows runs native. However, I've also read that Apple hasn't done a thorough job updating the drivers and that things like the trackpad may not work, or work as well, as using a virtual machine. And then there are the other advantages of using a virtual machine, such as being able to to switch back to my Mac apps. Any guidance would be greatly appreciated. Thanks.