A few months ago, when I started using IRC, I decided to use the Irssi client.
I found Irssi to be adequate for my usecase in all but one way: it doesn’t have an unread marker/indicator. I recently decided to switch to Weechat, initially expecting that having an unread indicator would be the only useful addition.
As it turns out, my expectations were wrong. Weechat is amazing! It has support for logging, built in mouse support and a really powerful interactive settings manager (fset). There’s also a nicklist that shows all the users in a channel, as well as a buflist for visually viewing all buffers.
All in all, Weechat feels much more polished and advanced than Irssi, and I think switching was well worth the ~2 hours it took me to configure Weechat.