I have been in Beijing for a year. It really improves your Chinese when you have to use it for everyday situations. Having Chinese friends to hang out with easily builds up your Chinese skills.

I lived in China for three years and just returned now.At the beginning I learned lots of Chinese and then I got stuck at a certain level and found it hard to make any progress (mostly I am just too old and lazy ;-)

u dont need to be prepared. just come to china, dont stay with other foreeigners and u will master the HSK 4 in 5 month. Thats the way I did. Its not hard, u only have to speak it whole the day. Well, of course, the best way is just to look for a chinese GF^^

But it makes no sense too, to live in china, but to stay together with foreeigners whole the time. Thats the reason why all of my friends over here are chinese. im staying here for 4 years, and I had never spoken any English.

Well, thats the point, ur right. One shouldnt learn it outside of China, that makes no sense, wasting ur time.