https://lemmy.dbzer0.com/post/1239735 - my previous IRC write-up from 3 months ago.
Been using AdiIRC for about a week now and everything works as good or better than mIRC.
I do recommend a different color scheme thou. https://dev.adiirc.com/projects/adiirc/boards/6
Horriblesubs was the biggest for a long time, but they closed shop recently. Subsplease.org would now be a good one, they even share the same irc archive as Horriblesubs so you can still access their releases.
They release torrents in the public trackers anyway. So I’m not really missing out on anything from them.