I think the Shenzhen immigration officers must be going through a personality transplant program... I went through Shekou ferry terminal a few weeks back and was addressed by the officer in very polite english ("good morning sir.... etc.), he even asked me to look at my passport then asked if it was ok if he stamped it in the location he pointed to...
It is chalk and cheese between the PRC officers and the miserable pr***ks you can get on the HK side these days.
One recent example was when I was shown to the empty residents cubicle during a quiet time at SZ Bay... I politely asked if the officer ('Fat b*****d') would not be quite so rough while handling my passport.... he immediately pointed to the 'Residents' sign and gave me my passport back, unstamped. I didn't have time to complain as I was rushing for a flight, doubt it would have made much difference anyway!