I thought I'd jump into this convo for a minute, since I was just in Hong Kong last week. I'll tell you my situation/circumstances and the outcome--hope it helps:

I was on a Residence Permit from Jilin but now I'm working in Jiangsu. My RP was about to expire, so I went to Hong Kong with all of my necessary documents and applied for the Z Visa. Granted, my passport did have previous Z Visas and RP's in it already. But I had no problems whatsoever in getting the Z-Visa. Super easy. It's now been changed into a new RP.

Good luck.

Nathan