I did the same job back in the mid-90's at the facility discussed in the article when it first opened. The piece rate was probably higher, though the measure we cared about was keystrokes per hour so I don't know if I ever saw a real statistic for this.
The work-load almost certainly has changed with technological improvement. Back then, my recollection is that we'd see more machine type than handwritten addresses, but only slightly. Also we were only filling in the gaps depending on how well the original OCR worked. Sometimes we'd have to key in the important portions of the whole address (house number, part of a street name, postal code)... sometimes just the postal code, and sometimes only a portion of the postal code. Some of these data entry modes were faster than others; the extended "zip code" data entry only required two numeric keystrokes whereas the full data entry mode required much more time.
The work-load almost certainly has changed with technological improvement. Back then, my recollection is that we'd see more machine type than handwritten addresses, but only slightly. Also we were only filling in the gaps depending on how well the original OCR worked. Sometimes we'd have to key in the important portions of the whole address (house number, part of a street name, postal code)... sometimes just the postal code, and sometimes only a portion of the postal code. Some of these data entry modes were faster than others; the extended "zip code" data entry only required two numeric keystrokes whereas the full data entry mode required much more time.