First lets look at the construction, a good solid frame consisting of a solid single molded plastic base and half of the jaw. It may be plastic but its strong and should hold up to the stresses of the hobby. The other half of the jaw is equally as strong, and the rubber grips that hold the models/parts seem well enough.
The biggest issue I have with this product is its suction base. It just sucks! I cant get this thing to grip for more then five minutes at a time, iv even tried plasticard. It requires a non porous surface to grip to, and those are hard to find around the home (at least my home).
For $18 you will get a good starter vice, but if you are looking for something that will stay put for more then five minute intervals I would keep looking.