When comparing KVIrc vs CIRC, the Slant community recommends KVIrc for most people. In the question“What are the best IRC clients for Windows?” KVIrc is ranked 6th while CIRC is ranked 18th.
Ranked in these QuestionsQuestion Ranking
Pro Plenty of customization options
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 Extensive documentation available
Help files and online resources show all of the feature and scripting capabilities.
KVIrc does not need to be installed. It can be kept on a flash drive and run from there.
Pro "One Identity" ability
Create a personal "bouncer" of sorts, using CIRC "/make-server" (/help make-server for more details) give you a connection so that you can using the same Ident/Nick from multiple devices.
Access it everywhere where Chrome is.
Pro Easy setup
Few clicks to install.