I just came back from HK.
I used my passport picture page to go through an e-channel auto- gate and I didn't have any issues.
I also visited one of the application offices just after the e-channel auto gates, and I asked if I need the barcode sticker, but the agent told me I wouldn't need the barcode as long as I use a valid passport. She didn't offer a new barcode sticker because my passport would work just fine.
Of course once my current passport expires, it won't work.