I'm not terribly happy with these chairs.  They are lightweight and easy to stack, and the price was right.  But they are just really REALLY uncomfortable to sit in, even for just a few minutes.  The dig right into your tailbone, and there's no way to get comfortable no matter how you sit.  And the aluminum means that any time the sun is out, these chairs will burn the heck out of you.  And if the sun isn't out, why are you sitting outside anyway?  Additionally, the chairs simply aren't very sturdy.  I weigh about 210 pounds, and I always feel like I'm gonna break the things when I sit in them; I can almost feel them buckling under my weight.  They work for now, but I will be replacing these when I get a chance.