I had trouble with my ott lamps about 3 years ago, I wanted to get them fixed because they were hit by lighting, not fixable, the transformers were somewhere untouchable, I was furious, $350 down the drain. I refuse to do business with them, I now have the knock offs, if it breaks and can't be fixed, I will just buy another knockoff.
Also, I purchased the full spectrum 48" tube bulbs for my ceiling ballasts lights in my studio - fantastic! I highly recomend. they lasted 9 years before I replaced them.