This.
My place of work has recently started replacing Cisco Jabber with Skype for Business. I'm assuming this is a purely financial move.
Jabber is clean, simple and has a functional and professional interface. It works, it's reliable, and it's easy to use.
SFB looks like something you'd expect to find on a kid's tablet - it's an awful childish UI that looks as business-like as a box of Duplo. I also find that it's far less stable and regularly crashes every couple of days as well on my machine. Well, I suppose it's consistent reliability wise. Almost all parts of Office 2016 crash with alarming regularity...
Biting the hand that feeds IT
