The only downside to using Linux in the workplace doesn't become apparent unless you regularly exchange documents with people in other locations, be they coworkers, clients, or what have you. At that point, you will discover that people outside your office will send you Microsoft format documents and not only expect you to be able to read them, but that you will be able to modify them and send them back.
While a pure linux shop can just use "Libre Office" and whatever other tools work well for a given circumstance, that idea just flat out fails when you're collaborating with folks who are using current Microsoft tools. The people in the home office don't like being told their document doesn't look right because they used a feature that's standard in Microsoft Office 2013, but that LIbre Office doesn't implement or doesn't get quite right. They *REALLY* don't like it when they send you a document and you send them back something forced down to Word 98 compatibility format.
So, that's the headache you're setting yourself (and your boss) up for if you switch the office (or part of it) to Linux. If you're all internal, it's easier to work around, but will still become an issue from time to time. If you don't share documents often, then it's a moot point.