Skype for Business client and server both seem to work pretty well. What I find annoying is Microsoft conflating the branding between two very different products, a rebadged enterprise communications product (formerly Lync) and a commercial-consumer product. So when someone says they want to make a Skype call with a client, what do they mean? Sometimes it's Skype for Business and sometimes it's plain old Skype. It costs everyone time and money when this isn't communicated clearly and one end of the call expects to use Skype and the other end Skype for Business.