Just bought 2, tried one in the garden tonight, yes they are great, just cant bang them into the ground! So dont use them in the wind! You can use guy lines though.
I saw them advertised and thought of getting one myself. We have the material type windbreaks, which once again can't be hammered into the ground so have to use the guy lines. I've suggested to OH that we tape some pegs to the bottom of the poles and hammer them in - Don't know if it works but will give it a try in a few weeks
have just tried mine out, and those poles wont last 5 mins in a breeze i have now swapped my old windbreaker poles and put them in instad of the metal ones, i bought two blue ones, so i have also unpicked one of the roof canopies, and made a further windbreak out of the spare wooden poles that i have, i still think they are worth their money even if i have had to make some minor adjustments, i have now ended up with 3 windbreakers instead of 2