4 wheels can be inherently statically stable but requires more space and requires more energy when running (counter-intuitive, but if your balance algorithm is efficient, you use less energy wheeling around on 2 than on 4 because you can basically play games with gravity to get some acceleration tradeoffs... And you have half the number of powered wheels, assuming you're 4-wheel drive).
If they solve the hard math, the end result may very well be a more performant machine (though as someone else in thread has noted, depending on the overall goals, a zero-wheels statically-mounted arm could be better still).
BD's machines actually have terrible energetics. They use very heavy and inefficient hydraulic actuation. I can't find a source for it, but IIRC Atlas has a specific resistance of around ~40, compared to a human which is around 0.2. I don't know an RC Car is at, but direct drive motors are quite efficient.
4 wheels can be inherently statically stable but requires more space and requires more energy when running (counter-intuitive, but if your balance algorithm is efficient, you use less energy wheeling around on 2 than on 4 because you can basically play games with gravity to get some acceleration tradeoffs... And you have half the number of powered wheels, assuming you're 4-wheel drive).
If they solve the hard math, the end result may very well be a more performant machine (though as someone else in thread has noted, depending on the overall goals, a zero-wheels statically-mounted arm could be better still).