When comparing IRSSI vs Polari, the Slant community recommends IRSSI for most people. In the question“What are the best IRC clients for Linux?” IRSSI is ranked 4th while Polari is ranked 9th.
Ranked in these QuestionsQuestion Ranking
Pro Perl Scripting
Allows the user to create and use perl scripts to perform actions.
Pro Persistent Connection
Pro Command line outputs can be sent to a channel or message
/exec -o figlet "Slant.co"
Allows the modification of IRSSI's look and feel.
Pro Free and open-source
Pro Has a plugin for encrypted communications
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.
Polari integrates nice with GNOME, on a visual and technical level. It uses GNOME online accounts and runs empathy in the background.
Con Gives little direction upfront
Actually, Irssi.org has it's own GREAT documentation.
Con Cryptic configuration files
Con Can't do vertical splits
Untrue, there are perl scripts available to do split screens with
Con No GUI
Actually a plus, lower memory overhead
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.