While Google Docs has been cutting into the Microsoft Office user based since it was introduced in 2007, Microsoft has finally fired back with its Office 365. A little too late? No, says Microsoft. While Google Apps (which contain Google Docs) is used by 3 million organizations and about 30 million people and counting, Office has 1 billion global users, Microsoft claims. In fact, Office has been Microsoft’s top selling product, accounting for 30 percent of the company’s $64 billion in revenue last year. So is it time to upgrade your free Google Apps to Microsoft’s smoother driving Office 365? Office is obviously pricier, but it also has better functionality. It includes all the standard Office programs, but with cloud features including Web-based e-mail, shared documents, shared calendars, instant messaging, video conferencing and Web meetings, and websites. It will also include Skype, once Microsoft's acquisition of the company is finalized. Office 365 starts at $6 per user each month for the Professional and Small Business plan. The Medium Business and Enterprise plans range from $10 to $27 per user per month. With as large a user base as Microsoft holds, they will most likely have an advantage in the enterprise and small to medium-size business arena. Documents that are made in Microsoft Office often don’t easily translate to Google Docs without some formatting changes, which also give Microsoft a leg up over Google Docs. But right of the gate, Office 365 has some issues. The cloud-based versions of Word, Excel, and PowerPoint offer only a subset of the functionality of their desktop siblings. Users will still need to invest in Office software to tap into all the advanced features. iPad users who downloaded the trial version of Office 365 reported a number of problems with the features. While Office 365 isn't Microsoft’s first foray into cloud computing – the company offers cloud services to enterprises — it's certainly the largest. Even with the subscription fee, the Office 365 might become a business staple, rather than a consumer necessity. Graphic: Microsoft