My two cents on train travel in China--

I took two overnight trains in a three day period a few weeks ago. Both were K trains and I took one hard and one soft sleeper.

The soft sleeper was more luxurious but as jiejie had warned, I felt very uncomfortable being in a tiny, closed room with three men. Especially considering that all three of them watched me for hours until the lights were off. I was on the upper bunk and the guy across stared at me directly and then the guys on the lower bunk watched me through the mirror on the door! None of them had brought books or any form of entertainment, so I guess I was it. I would not recommend this for women traveling alone. It didn't feel unsafe, exactly, it just felt creepy.

The hard sleeper was much better because it wasn't an enclosed space, there were more people and there were more women.

I can't say that I got much sleep on either, to be honest. The train stopped every 30 min and this woke me up every time. If I were to do it again I'd take a sleeping pill.

I ended up opting to fly rather than take a hard seat trip. A girl I was traveling with said it was one of the worst experiences of her life. She said that any time she did try and fall asleep she'd wake up to the sound of camera phones taking pictures of her! (She is blond)

Overall I am very glad I took the train in China, and would recommend a hard sleeper. That said, now that I've done it I think I'd usually rather fly if the price isn't too much more (and it usually isn't).