I was so disappointed that CL's apartments couldn't be built in other worlds that I waited until it was half price. Once I got it, I was happy with it. The Singing Skill was one of the highlights for me as well. It was pretty in depth as far as all ages being able to sing together in pairs, and a pretty big amount of songs. Plus you can sing and play piano and guitar at the same time. I hope they add a band ability, and singing together in larger groups, and a singing career at some point in another pack.
I do like the careers with the Work At Home option, too. It's quite easy to work around to accomplish the goals along with another interest, or if you have a family, etc. They pay pretty well, too. One thing about the politician career is that their speeches never seem to attract anyone to listen to them. I semi-solved that by utilizing Get Together, and having them give their speeches at a Political Club Hangout. The hangout is usually a venue, a Cafe for instance, that has other townies using it as well, so it seems less empty than using that podium that is in the Uptown section.
The world is pretty well done, too, and seems busy enough for a city atmosphere. The festivals are quite well-attended, especially compared to TS3, where only a few straggler Sims were at the events/venues. The street performers help a lot to give a crowd vibe as well.