This is a general response to the entire forum (not just to Zanaelf).
I too HATED not having a sidebar in iTunes 11, but then I made myself get used to not having it BEFORE the enabled adding it back in the next revision. After a few months, I actually didn't miss it as much as I thought I would and I like they implementation even better in iTunes 12. I think you have to give it time, and by that I mean real time without the option of always having it there. AS for those who say that you could control eveything from Sidebar view.. they simply moved a few elements to the top that are always there. You can still control everything like you could before. it's not more or less "Intuitive" as it was before, it's just moved the side to the top. It's simply just different.
Another cool feature that may have been mentioned it that if you are in ANY other view than sidebar, (Music view for example) you can drag an album or selected song, or movie, or podcast, and start to drag it to the right and your sidebar playlists sidebar will Appear automatically.. This allows you to add music, movies, Albums even to your playlists without having to be in playlists view. Once you drop the selected media into your playlists, the sidebar will disappear again out of the way. This still may not be your ideal situation but it's a cool effect none the less (kind of like dragging optical media from the desktop to the trash can watching it change from a trash can to an Eject icon.
I'm not trying to jump on anyone here. I'm saying try it for a month or two.. You may find that you After you get used to it, it's not so bad. You still may PREFER the sidebar back, but find that this current isn't so bad.
One last thing is that if you leave iTunes in Playlist view.. you can still see playlist view when you re-open it...(with the sidebar out). Just breathe and give it time.. it's really not SO bad.