I was watching this video and at first glance it seems a good idea. Some people say that it was never used due to maintenance costs or efficiency, and in the Wikipedia page it is just mentioned personal differences between Geoffrey Pyke and the developing team. Even if it were expensive I can imagine situations were it would be better to have one of these instead of another tracked vehicle, so what am I missing?
Biggest problem is they can't run in certain places. Trying to drive one on a road results in really poor performance and usually some damage to either the screws or the road. They also don't do well in really fluffy snow. If the snow doesn't have enough moisture they just throw it behind them and dig downward without getting enough thrust to move forward. In water you have a limit on speed as cavitation can become a problem if you try to go too fast. Operating them in beaches or other sandy areas works really well but the sand wears the flighting. Pretty soon you go from normal to knives to nonexistent auger flighting. Overall the speed was never equal to tracks over most terrain. Hollow pontoon like screws can be penetrated by bullets and then start to take on mud and water which can really affect performance.
They work great in marshes and in sludge or thick snow. But they are a vehicle that only works in the right special circumstances.