Integration with Microsoft Outlook and Active Directory. It's easy to find colleagues and organize meetings with them.
Almost everything else. User interface is a little bit old style, features are the same as Skype core features.
So it appears as a downsized, downgraded clone of Skype. The only good feature is the the meetings invitation through Outlook: a Skype for Business link is sent with the invitation email, so participants can join easily. There is also a web client so external participants don't have to install the client software, which could be a little bit tricky expecially for users that are not administrators of their computers.
However, in my experience, meeting that involve people outside the organization can't be accessed unless you use the web version (which is a mere duplicate of the client version - so why maintain both?)
There are many many free alternatives to do the same thing, such as appear.in, Cisco WebEx, join.me, Google Hangouts... and the classic Skype of course!
Skype for Business seems not to have anything special to offer, but it comes together with the Office 365 Suite, so why not give it a try if your company already own it.
It comes with Microsoft Office 365 suite. So, if in your organization you use Outlook, Word, OneDrive, etc. it's a simple, out of the box, solution to company video meetings.
In other cases, there are many products that do the same thing.
Easily organize video meetings with colleagues and clients.