I hated the idea of a cloud-based Office before it launched, but I signed up this past spring and have been rather impressed. I need to install the suite on multiple PCs, sometimes juggling around, so I like the fact that there's no hassle in deactivating and reactivating licenses... because quite frankly, ringing up Microsoft's customer support line is a major chore.
I still like the idea of boxed copies, but since Microsoft prices those to be stupid expensive, I'm glad Office 365 is at least a really good value.