I am in the process of purchasing a 4wd buggy. I am in between the HB D413 and the Kyosho ZX6. I mostly race on indoor clay. I like the innovative design of the D413, however I already have a RB6 and an RT6 and they are working very well for me. 4wd buggy is still a developing class at my home track so I don't have any examples of either car to put my hands on. Any experience with both buggys or any advice would be greatly appreciated.