The ecobutton doesn't it turn off, but it seemingly does something to your PC because the FAQs warn that some older computers and certain HP PCs may have trouble reactivating due to BIOS issues. I think that means problems. Yet it has won major, major awards. One was the 'Most Innovative Green Product' Award at the 2008 ASI Show, Orlando USA. And it has logged up German and UK awards for, oh, I hadn't read that properly, best promotional gifts of the year. And ASI stands for Advertising Speciality Institute. The new seal of Green approval. surely.
The funny thing is how the Green fraternity hasn't rubbished it. But, you say, surely it has 'eco' in the name. So that's all right then.