The kevlar-coated fabric audio cord is definitely durable and anti-tangle but unfortunately it's only for the part connecting the Y-splitter and the 3.5mm audio jack.
The cables from the Y-splitter to the earbuds are just rubber coated and disappointingly flimsy (it's actually thinner than what you find in most earphones).
Other than that, the SuperDarts is one of the few earbuds that bring the best of both sound and build quality. A rare combination of deep bass and superb clarity easily places this product among those priced twice higher than it.
*Side-note, the original rubber buds that comes with the Superdarts seem to be quite a dust magnet.