The native Mac client is very slow compared to either Slack or Hipchat when switching between channels or replying to a conversation.
Please improve the performance of the application.
Richard Hurt commented
I have noticed that trying to scroll back and find earlier messages is very slow. The scrolling happens quickly but it takes several seconds for the messages to be retrieved and shown on the screen. In fact, I have a chat session on my screen right now that has not updated at all when I scrolled back to see earlier messages.
This is a real problem on fast moving chat windows. Trying to see what people said earlier in the conversation is very difficult and takes more time than it should. I don't know if this is a problem with the client or the server API not being performant.