The "magic" is chiefly in the degree and quality of the hand-sewing. Since the pants are already nearly all hand-sewn (virtually all hand-sewn if you buy the "golden" ones), it is hard to imagine anyone else doing its equal in that respect. Rubinacci, for example, makes excellent trousers--but they cost me twice as much and have about 60% as much hand-sewing. Who cares about hand-sewing? Well, I don't know if they make 'better' pants, but I appreciate the artisanal workmanship regardless of the function or aesthetic effect. If you don't get that, a pair of Ambrosi's aren't for you.
Plus, the price is relatively low. Most bespoke trousers from a top tailor will cost more than $1,000.