In reply to MonkeyPuzzle:
In my experience the cheap plastic ones tear around the pop studs within a week or so of use and considerably less time in a moderate wind. Even the more expensive Salewa one I have, which is made of PU coated nylon, had the pop studs tear out on a day of about force 6 winds in Wales.
They are fine for use on a wet not very windy day though, especially in the tropics.
You used to be able to get coated nylon ponchos, which chunky metal pop studs from Army Surplus shops and probably still can. They came in a couple of varieties, rather heavy duty Army surplus ones which were strong and lighter ones which were less waterproof, but about £10 (10 years or so ago). Putting silicon tent water proofer on this second type made them much more useful in our wet climate.