When ordering stuff from China, always try to use DHL is possible. DHL seems to always get their stuff through customs with no issues...unlike UPS..
This may be true for where your shipment enters the US. While I haven't had any major issues with DHL recently, I've had a few shipments held up due to minor paperwork issues. FedEX, on the other hand, is almost always a problem. I get the package, but it comes with a extra invoice for handling customs inspections, which doesn't happen with UPS or DHL.
Anyway, it all depends.