Google Drive is incredibly useful for sharing documents so you don't have multiple versions. It's easily accessible from anywhere, since it lives online, and sharing/collaboration are simple enough.
The spreadsheets aren't as robust as Excel. They're lacking in several simple concepts and it's a little clunky to use, by comparison. It needs work. But it's free and easy to collaborate one.
Word docs are pretty basic, but they get the job done.
Google Drive integrates easily with some other programs (Smartsheet for example) which is helpful. You can also open & save any email attachments to your Drive, which is helpful. Organization is pretty straightforward.
For home use or SMB that don't require a complete Microsoft Office set up this is the way to go. You may still require some Office products, they're more robust, but it could save time and money using these Drive tools.
All in all a good tool to add to your toolbox.