My row cover from Pinetree Garden Seeds came last week and I was really happy with the product. Pinetree was the only company I found that allows you to order by the foot. I only needed 20 feet and many of the prepackaged row covers had 50 feet or more. The row cover has 2-4 degrees of frost protection, transmits 85% light and porous to water. According to the catalog supports aren't needed and it won't crush delicate plants.
This weekend I put it over what's left in my garden. We had our first serious frost since the temp dropped to 24 degrees. I attached the cover with lawn fabric staples and didn't use any hoops or support. The fabric protected everything perfectly.
This Fall I am experimenting with the row cover to see how long it will protect the lettuce. If it proves to continue to work well next year I might invest in support hoops and clips so as to not damage the cover. I have already pulled the cover up because this week we will be experiencing an Indian Summer with temps in the 60s. There are holes from the staples and I will only be able to put it back on and off a few more times before there will be too many holes.