Great service, but a bit spoiled by being a web app

Slack itself works great and is very well designed, easy to set up and integrates smoothly with most of the online tools currently available. However this app suffers a lot from being essentially a web app wrapped in a native shell (i.e. most of the UI is actually a web view). It doesn’t make it unuseable, just much less polished than the average OS X app.

Guillaume Laurent about Slack for Desktop, v1.0.2