Work on any device, with same functionality and view. True real-time collaboration. Integrated domain. Perfect for Small Business. Excellent value for money. Deployment simple and straightforward. Support is good, plenty of good forums, KBs, how to videos also.
Requires internet connection. Functionality little limited, compared to offline standard competitor apps, but this is getting better.
I considered Office 365, including using trial, but it lacks the flexibility and still requires purchase of local licences. Not as scalable, due to need to change from base plan to whole different plan but without migration path. GApps is totally scalable and flexible.