I have taken BP twice a week for the past 3 months and really enjoy it. The class is choriographed but a new program is released every 12 weeks that changes the moves, and music. When I first began, some moves I did with no weight at all. I figured my caboose was enough weight to lift by its self :lol The bar is approximately 3lbs (if I remember correctly), and the plates come in 1kg, 2 1/2 kg, 5kg, 10kg, ect. And you can stack 3 plates on each side of the bar. So IMO there is plenty of room to grow within the program. Hope that helps, and you have the opportunity to attend a class.
ETA: I know it's not considered cardio, but (depending on your weight of course) it really can get your heart rate up. I wear a HRM to track my calories (I'm on WW) and I normally burn 300 calories with an average HR in the 130s. Not a WHOLE lot, but I'll take em where I can get em
