I can very much recommend this! Recently discovered it, and started gathering all my chats into Slack (you can of course do it in others). Especially getting Freenode and other IRC servers at the tip of my fingers in just one client, is a huge deal.

Of course, I could also just connect to everything through IRC (at least for Slack<->IRC), but the Slack client is a lot nicer on mobile than any IRC client I know of.