My experience with Lync is different. My current employer is a windows shop and uses Lync for communication.
What I don't like with Lync
1. Screen sharing sucks. Its slow. Is it possible for them to use a technology similar to FreeNX?
2. Does not support multiple-client notification. I use multiple desktop and when you are logged on multiple Lync clients, messages will only go to a single client!
3. OSX client always crashes
What I don't like with Slack
1. Cool UX but sometimes the UI hangs and shows only a white, blank space
What I don't like with Lync 1. Screen sharing sucks. Its slow. Is it possible for them to use a technology similar to FreeNX? 2. Does not support multiple-client notification. I use multiple desktop and when you are logged on multiple Lync clients, messages will only go to a single client! 3. OSX client always crashes
What I don't like with Slack 1. Cool UX but sometimes the UI hangs and shows only a white, blank space