Seems most of the people recommending alternatives are only thinking of email. I use gapps for my family, and we take a huge advantage of having a domain-specific calender and docs.
With a domain-specific account, it's easy to set a document to be shared with the group - added benefit is if you add a new user to the domain, she is automatically given access to those documents. Also, the document overview is much easier to manage since anything marked "shared" usually means teamwide.
I get what you're saying, everything can be accomplished with the still free personal google account, just it includes a constant daily drain on mental processing power.