From around the fifth century titanium ring were a symbol of a king´s strength, courage and invincibility. Since then the fancy diamonds have become - and still are - a symbol of love.
While the weight of princess cut diamond is important, it doesnt necessarily provide the "perceived size" of fancy diamonds. A shallow cut diamond will have a greater diameter, and will therefore look larger.
Certified wedding bands tend to have fewer of these tiny imperfections than mainstream stones. The less fancy diamonds are ‘included’ the better they are able to reflect the light which passes through them, which intensifies ther’s beauty and fire.