These look as good in person as the pictures and are of surprisingly good quality.  They have solidly built bases seats and cylinders.  It took about 15 minutes to assemble 6 chairs, though I had a socket wrench.  Expect double with the included allen wrench.  Like others have said the plastic ring is useless and doesn't add anything to the style.  I'm not sure why it is even included but I did install mine.  

The only real downside is that the cylinder needs about 120 lbs to compress making it a pain to adjust down for lighter people.  I broke the handle in one chair thinking i hadn't actuated the cylinder when in reality my 115lb teenager just didn't weigh enough.  The lever handle is fragile, but won't break unless you ham fist it like I did.  Squeeze slightly and put the extra weight into the seat cushion and you are fine.  I kept squeezing until I broke it, but it didn't take too much effort to do.

Pros: Value, style
Cons: stiff cylinder for lighter folks, useless ring bezel