So, have you tested it yet? In rain and wind?
There is a member here (Topshot) who has a pretty good write up about turning a really cheap plastic sheet into something that is actually durable.
Also, for a few dollars you can buy a space blanket, which is more durable than a cheap table cloth. You can also buy a nylon 5X7 tarp for about $9 at walmart.
I've taken a vow of poverty. To annoy me, send money.