We consider a lower weight better because lighter devices are more comfortable to carry. A lower weight is also an advantage for home appliances, as it makes transportation easier, and for many other types of products.
A metal mount is generally superior to a plastic mount as it is more durable.
A wide angle lens is great for capturing larger areas of a scene, such as when doing architectural or landscape photography.
A shorter minimum focal length allows you to get more of the scene in the photo, and offers a wider angle of view than longer focal lengths.
A longer maximum focal length allows you to focus in on a small part of a scene, and offers a narrower angle of view than shorter focal lengths.