They didn't work at all. They didn't turn on. The first time we bought them we also purchased extra bulbs, and the lamps would not turn on with the other bulbs, either. We suspected that the lamps must have been damaged in shipment.
It was months later (although from the same JoAnn's, so may have been same shipment) that we tried again, this time with the floor models, but we had the same problem, so we gave up. I haven't tried again.