I don't really do much of that type of training, but I was wondering about a similar type of shoe recently when I took up dance (jazz) classes again. I actually went and bought "dance sneakers" that were both stable, flexible and lightweight, but I ended up using my old Nike Free 3.0. Possibly not stable enough for heavy weight lifting, but certainly flexible and narrow enough for tight moves without stumbling.
I stopped worrying about cushioning after I started running with a midfoot/forefoot strike, with minimalist shoes. It took a little getting used to, but now my calves are strong enough that landing on my forefoot with very little cushioning is not a problem. Mind you, I don't do long distances, but they're fine for say, 6 miles. I would guess that for your cardio moves you rarely land on your heel anyway?