When comparing Konversation vs Polari, the Slant community recommends Konversation for most people. In the question“What are the best IRC clients for UNIX-like systems?” Konversation is ranked 5th while Polari is ranked 12th. The most important reason people chose Konversation is:
Konversation is still being updated with new features and bug fixes. Konversation 1.5(released January 15, 2014) has added plenty of major features.
Specs
Ranked in these QuestionsQuestion Ranking
Pros
Pro Regularly maintained
Konversation is still being updated with new features and bug fixes. Konversation 1.5(released January 15, 2014) has added plenty of major features.
Pro Notifications
Konversation has an OSD(On Screen Display) feature that gives you an overlay message anytime your nick is mentioned. This means you won't be interrupted from your work and reduces the need to keep the window open.
Pro Plenty of useful smaller features
Koversation is full of features to make IRC simpler and smoother. It comes with tools like a channel bookmarker, the ability to insert special characters easily and the "URL catcher", which gives quick access to any links mentioned in the channel.
Pro Quick Buttons
The Quick Buttons features allows you to set a button to any IRC command that you frequently use. It has several defaults such as whois, and kick but a button can be created for any command you need.
Pro Very professional UI design
Pro Great UI
The CSD-based UI is great to look at. No screen space goes entirely wasted and is presented neatly.

Pro Easy to use
Polari is very straight forward to use.

Pro GNOME-Integration
Polari integrates nice with GNOME, on a visual and technical level. It uses GNOME online accounts and runs empathy in the background.
Cons
Con Updating to a new version overwrites configuration settings
Colors, fonts and autojoin behaviors may be customizable, but backing up the settings prior to updating the software is imperative.
Con Crashes when trying to download search results (on Ubuntu 16.04)
Con Some advanced features are lacking
Polari's users will find some advanced features lacking, such as Direct Client-to-Client (DCC).
Con May seem too simple
Unlike Hexchat or other alternatives, it does not expose much of its functionality though some of it might really be present.
