The HBK2 is only slightly bigger than the blade cp (little bit longer and taller because of the bigger/slightly more complicated rotor head assembly). They handle quite a bit differently though. The belt driven tail makes a big difference. I have my Blade CP+ setup kinda "lazy" though, flat bottom blades and low head speed, I could probably set it up to handle more like the HBK2 but it'll never be the same.