Where are you?
There is no difference between American lawyer and Chinese lawyer. The most important thing is that you find a lawyer who can really do a good job.
I tried to avoid Chinese lawyer at the beginning and found one American: "Jefferey Bloom Lawyer Firm". He charge me $2000 for I-140 and I even did not have a chance to talk to him. His assistants did my case (a bunch of Fujian Chinese) and have very very bad attitude and I have to find another lawyer (Mainland and Taiwan Chinese). If you are in NYC or NJ area, avoid him!