I moved myself to this, along with the family plan ($99/USD/yr, IIRC). The nice thing is that you can still buy the Office suite separately if you want. The other thing is I finally wanted to settle on "one" cloud storage provider for me and my family, so the addition of OneDrive sealed it when combined with Excel.
Honestly, Office365 is something of a model for the SaaS software I've bought: the core offering (Office) is still available with an eternal license, but the SaaS offering is very good, well priced, and the value add of OneDrive is great when competitors charge for storage separately. There are a lot of issues with SaaS (velocity, feedback loops) but they did this one right, I think.
(The funny thing is I have an iPhone and almost exclusively use Linux, so obviously I live in a bizarro world.)