It really has to do with your motivation and focus as well as personal learning style.

I like group for social but you won't ever be able to do much more than dance socially. WHich is great and a lot of fun.

The other thing to watch for is that as you learn it will get easier. Learning dance is a very different way to acquire knowledge. Your brain has to learn the method which is part of what takes so much time. Once you've gotten used to learning steps and learnign choreography and the basic vocabulary it will all get easier and faster.

Good luck!