I absolutely LOVE this set!  It was a little difficult to put together, the holes are not lined up perfectly, but if you wiggle it a bit, and don't tighten the screws one at a time it works just fine.  The bolts will come loose with wear, but they are easily tightened again with the enclosed allen wrench.  My husband suggested putting some lock-tight on the screw to keep it in place.  
They look great on my patio and they're super comfortable.  It's tough for me to purchase chairs that both my husband and I are comfortable in.  He's 6'3" and I'm 5'2".  We were so pleased, we bought another set!