Good advertising, but how well does the product work? That point isn't really addressed. Even their website is more concerned about case covers than functionality. I suppose that makes sense as they're primarily marketing it to children as a fashion item, but I think functionality would be rather important to anyone who had a use for the product.
Even if it works only fairly well, that very low weight and cost would make it a very good thing.
Old tech now, saw the video ages ago.
Newer prosthetics are tied into the nervous system.
Yes, but they don't cost £2000. The cutting edge stuff can't be bought at any price because it's not yet a product. I've seen video of an entirely mind-controlled artificial arm with strength and speed at the high end of human normal, an even higher range of motion than human normal and a fully functional sense of touch on the finger and thumb tips. With not much training, the wearer's brain integrated it into their proprioception, i.e. it became their arm. That's spectacular...but it's a prototype and it required a specialised amputation operation by a specialised surgeon to make the stump suitable for the artificial arm and several specialised engineers to customise the arm and software to suit that specific person. It's not available at any price now and when it does become available it will cost a great deal more than £2000...and it will probably be "old tech" by then in the sense that there will probably be a prototype of something better.
The problem with making artificial limbs stronger and faster than the originals is that you end up transferring excessive loads to the wearer's skeleton and that won't end well.
That's true, but there are some other options for the "superior to normal arms and legs" idea.
Reading through the advertising spiel for this product shows the beginning of a simple example of that - this product has a greater degree of wrist movement than a human wrist. Being able to rotate your wrist 180 degrees so that your hand faces the opposite way and is still fully functional is superior to human normal and there are probably some situations in which it would be useful. A more advanced artificial arm could have more advantages in terms of possible ranges and types of movement.
Locking grip and precisely controlled amount of grip could be useful superior functionality in some circumstances, even if the amount of force applied by the grip isn't higher than normal human grip strength. Higher than normal human grip strength could also be possible, since that load wouldn't be transferred to the wearer's skeleton.
Increased resistance to damage is another possibility, essentially making the artificial limb armour/protective clothing. Current ones are too fragile for that, but it's a possibility for the "superior to normal arms and legs" idea without making them stronger and faster than the originals. Being able to hold very hot objects, put your arm in fire or in corrosive substances isn't likely to be useful very often but it is superior to a normal arm and might sometimes be of some use in an emergency.
On a lighter note (but probably one that would be much more useful to many more people) - integrated "phone" holder.