1. It's no more complicated than an alarm clock in a hotel room. Most people can manage that.
2. Depends on what you compare it to. It' about the same price as a game console (and could be as much fun), and is 4 times cheaper than a portable EEG machine (which is the only way to get the same quality of sleep data).
3. I didn't have any problems with it - it's very light.
The only problem for me is that some day I just collapse on the bed and the last thing I think about is putting it on. So I have large gaps in my data. But I have data!
The only problem for the company is that there may be not enough people who care about the data. On the other hand doctors may be slow and reluctant to accept this device's data too, so this leaves not much point for most people in having one of these. It has a potential to end up being a geek toy with limited appeal.