I think the large wheel design is really good. It can withstand spinners better, keeps everything safe and great against flippers. However, their drawback is stability; if you intend to use it upright (flippers aren't really good both ways up), then it's going to roll itself over quite easily, not to mention control issues, they aren't exactly the most manoeuvrable and good positioning is vital or a pneumatic setup or else you're going to waste a lot of CO2. The design itself is good, but for a torque reaction axe mostly, which is what I'd recommend. Pneumatic systems are also quite difficult, especially for a first time builder (on this scale). Regardless, I wish you good luck and welcome!