I cannot wait to try Zumba! Unfortunately, my gym hasn't offered it before now and it was far too expensive to take anywhere else, so I am waiting until my gym starts it up next month. I'm so excited!
My girlfriend has taken it at our local Y and found she had really high calorie burns while having a great time. I've also heard really good things about it from other friends who've done it, and my gym staff had a ball during their demo. I'd say go for it!