Hey just wanted to add my 2 cents. I used to dance quite a bit, but sadly quit this year. I'm hoping to start again in a very near future.
In any case, I took ballet, i started when i was about 7, but i knew i was never gonna become pro. I did it for posture, and for the basic steps for other dance forms. But people who see me immediaty say "you've danced", and that i owe to ballet. At one moment, I danced in a really small school, mainly as a favor to a friend, and a woman came to our class, and she had never danced in her life, and she was in her 30s. With ballet, don't expect to become like the top dancers you see ( aka stick thin) but you will definitly build some new muscles, gain posture, and feel all around good, because even though it will be hard and frustrating, if you really stick to it, you will see results, and that will be great for your body and soul. Sorry if I sound a bit melodramatic!! Have fun dancing!!!