I have the 1st release of the VF-11 and the FAST pack version of the YF-21. The VF-11 feels like it could break when I try to transform it to fighter mode, and with all the hoopla regarding the breakable hip joints, I've just kept it in battloid mode. With the YF-21, it's a pretty nice looking piece in fighter mode, I half-heartedly tried to transform it to robot mode, but I thought it'd look nicer in fighter. It's a very sturdy toy though and feels a lot stronger than the ver. 1 VF-11.