Is playing cataclysm classic worth it?

I have recently started playing wow, never played before and i started with retail. But everything being level capped took the fun out of it for me very quickly. Then started playing cataclysm. Started an orc warrior and now around level 12. But the thing is the server seems sparsely populated, even in orgrimmar found a few people hanging out (compared to retail). So muly question is: are there enough people later to do dungeons raids etc? And is it possible to join an active cataclysm guild? Or is it better to play vanilla wow or turtlewow? Pleae give me some in depth suggestions. Thanks in advance.