Your experience may vary, but...
I have had terrible luck with sending regular packages to individuals in cities outside of Beijing and Shanghai. I haven't kept records, but I would guess that more than a quarter never make it at all, and that another quarter have had parts missing. I was so disappointed in this that I started using USPS Global Priority envelopes when I could and DHL when I could not. Since I made this change, I have never had a problem. The Global Priority service is quite fast and pretty reasonable, so you might consider that option if what you're mailing isn't too big.