I did not hear many positive stories about 3G in China so far, and I therefore hesitated to buy a 3G connector for my laptop. But yesterday I decided to give it a try and bought a Huawei 3G USB connector for my MacBook Pro. So far I am very happy with it. Until now I normally used a GPRS connector to go online at places without wifi, but the speed was so slow that it was hardly workable. 3G makes a huge difference. I did not measure the exact up- and download speeds yet, but it seems quite similar to the wifi connection that we have in our office. But maybe speeds will go down once more people start to use 3G?
I bought the 3G connector at the small Apple retailer on the 2nd floor in the new computer market on the corner of Xizang Road and Huaihai Road, next to Times Square. The price is RMB 450 and you pay an additional RMB 100/month for 60 hours of usage (for RMB 200/month you get 200 hours). For me 60 hours is enough, I mainly use 3G when driving to and from work and when I am at Starbucks having a coffee.
Dialing up takes about 20 seconds, disconnecting about 10. I lost my connection only once so far while driving through Shanghai, so it seems the connection is relatively stable. The guys at the Apple counter installed it for me within minutes (ask for Roy, he is an expert and also speaks English fluently), but it was so easy that I could have done it myself as well. If you want to be online everywhere in China (well, in the main cities at least, there is no 3G coverage all over China yet) I recommend you give this a try.