Tungsten is almost twice the density of lead, compared to lead, tungsten is a much harder metal and tungsten worn weights will be much smaller than the size of a lead weight in same weight class, so that tungsten Worm weights are less Hang-up.
Tungsten worm weights send more vibrations to the line since tungsten is denser than lead. It is going to from bouncing off different type structure allowing you to have better feel, more sensation than with lead and better than brass because of the small diameter making it easier to penetrate thick cover. Most tungsten worm weights also have a friction reducing liner inside them which causes less wear on your line. Less wear could mean less fish broken off.
Tungsten Worm weights are environmentally safe.