Ok, just a few points from a terrible pirate...
I used to use IRC (mIRC is just an IRC program), but it can be challenging to find non-0day releases and very challenging to find servers/chans that will live with good content for more than 6 months. The benefit of IRC is that you can go gung-ho with leeching, particularly on channels with xdcc bots.
oink.me.uk is the best for content and for speeds. It is very hard to not find what you're looking for on OiNK, and if you can't find it, upload until you're a power user and request it: you're request will be filled. There are a couple of challenges with OiNK: a) you have to maintain a ratio, and b) with so many users, it is tough to keep a ratio when 100 people are seeding it back. I have a dedicated server that I use as my seedbox, so it's never an issue for me. Downloads are extraordinarily fast, because that's the nature of a p2p design like torrents.
If you enjoy using IRC, you should try switching to newsgroups; sites with good retention will have much of the same content you will see on IRC, but will always max out your download bandwidth with no sharing required.
Lastly, as an OiNK user, I wouldn't recommend inviting someone that you don't know or trust: if you invite a cheater, you will be punished as well, so keep that in mind.
BTW, I know someone mentioned that IRC gets every 0day release before any other site, but that's simply not the case: for music, most stuff comes to IRC from sites like oink.me.uk, filemp3.org, indietorrents.com, etc.
If you have questions, ask.
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