I keep them closed, often even during the day. I'm a bit paranoid about my privacy. I also don't like waking up in darkness however, but these days the curtains don't make much difference in that anyway.
It is too dark. I don't mind it in the evening, gives me opportunity to light candles and stuff, but I hate it in the morning. I already have so much trouble getting out of bed in time and darkness makes it worse. I should have one of those daylight alarm clock things.