Greetings, and Welcome!
IRC is at irc.oftc.net #siduction
siduction is Debian Sid. We use the official sid repos for all Debian packages. The siduction repo provides the distro-unique packages, artwork, and in some cases specially-adapted (ie. fixed) packages -- driver packages, etc.
Of course other repos can be used if needed (debian-multimedia.org, debian experimental, kdenext, etc.), but the new user is advised to start with the default repos, and learn about the others as needed, and with suitable guidance.
I would say it is a "user-friendlier" Debian Unstable, but there is a reason why the first forum on the list is "Upgrade Warnings" -- the user does need to check that before upgrading, because of the occasional packaging issues in sid.
Feel free to ask questions here or on IRC -- and look through the prior forum posts to see the types of issues that users can run into.
Also, take a quick look through the excellent manual -- link on left. Especially review the section on upgrading and package management -- this is where you will need to learn a couple of new rules if you haven't been a sid user before.