I tried some a couple of years ago and they didnt last over three days. I belive that I just got some bad lights however. They are a neat concept, but they just dont go well with the 'natural' aquarium IMO.
Mabey if they had softer colors that actualy replicated 'moonlight', or at least the effect there off. All I have seen are the green, blue, red, and orange lights. The green looks ok, but just not enought light or color output from them.