When comparing KVIrc vs Polari, the Slant community recommends KVIrc for most people. In the question“What are the best IRC clients for UNIX-like systems?” KVIrc is ranked 7th while Polari is ranked 12th. The most important reason people chose KVIrc is:
Help files and online resources show all of the feature and scripting capabilities.
Specs
Ranked in these QuestionsQuestion Ranking
Pros
Pro Extensive documentation available
Help files and online resources show all of the feature and scripting capabilities.
Pro Portable
KVIrc does not need to be installed. It can be kept on a flash drive and run from there.
Pro Still active developement
Despite whats been said, development has been continuing at a steady pace on version 4.3.1 and more recently 4.3.2.
Pro Plenty of customization options
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 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.