I use DC a lot!
I've gotten a few on hard unlocked. I won't get DC2 until I get a new job. There's a Grease dance game out, I have the demo, I should try it out today.
I've tried your shape. It's pretty good! I ended up buying the Biggest Loser one instead (it was on sale ;p), and they are very similar.
Did you underestimate how hard the workout was too? I totally did..lol! I thought 'it's just a video game', but it whooped me good!
Did you get that adventure game with your Kinect? It's pretty fun, gets you moving. Also Sports (I haven't tried season 2 yet) is really good to get your heart beating.