What's so cool about Letterpress printing?

What's so cool about letterpress printing and why would I think about letterpress instead of engraving my invitations or business stationery?: "Letterpress is a centuries-old relief printing process. The basic theory remains unchanged over the past five centuries, though modern technology allows us to combine digital layout with traditional printing. Our designs are created on a computer which are in turn made into photopolymer plates through a photographic process. All type and images are raised up on the plate and form the printed image area, while the recessed areas surrounding the design do not print. The ink from the printing press is applied to these raised areas of the plate, which is then pressed into the paper. Letterpress printing imparts an unmistakable impression in the paper, giving a vivid, three-dimensional appearance."