i have used both the coated fabric and silnylon. the coated version is water proof and the silnylon is water resistant. believe me in a heavy downpour i want waterproof. silnylon becomes saturated with water and ends up weighing more than coated.

a poncho is the one item that goes on all my trips. i use it for cook fly and general rain protection. ever tried using a rain suit for cook fly or pack cover? ever pulled out a rain suit to sit on and prepare a meal? ever had to cover over a leaking tent with a rain suit?

now don't get me wrong, i carry a rain suit as well but for an extra layer for cool weather and walking thru wet high grass and course if it's raining or snowing.