I spend much of my work day in Office 2011. While I thought it was a big improvement over 2008 when it was released, it's always been very slow, rather buggy, and with a poor interface (tabs AND toolbars?!) Yes and unfortunately, MS Office is necessary for some of us, and there is just no replacement for the power of Excel. I've been playing with the new release of MS OneNote and I like the new interface. It's cleaner than Office 2011, but not as stark as Office 2013 for Windows. I really hope that MS is using OneNote as a template for the rest of Office 2014. If MS cleans up the rest of Office and improves performance, they may have a winner on their hands (for those of us who need it).