After 30+ years of receiving performance reviews that were not based on numbers, this is an interesting topic to me. One of my peers always would ask people how you felt after a performance review and everyone would share feelings ranging from demotivated to neutral. No one ever felt empowered.
Would this change if the performance review became completely objective, based on pre-negotiated numeric metrics? This would mean that there would be no qualitative review aspects.
I would not like this policy to be applied in most of the jobs I have held, because they were not about numeric performance. Most professional assignments are not about numeric performance, except possibly hours works.
If you choose to go this direction, you must be very careful about choosing the metrics and goals that employees are to achieve. It could end up like Management by Objective, which did not work out well. You may want to ensure the goals for an individual are balanced, somewhat like the balanced scorecard idea or the employee may excel in one area and not benefit the whole organization.
The rules and thoughts that are needed to select these types of metrics should be found in most Lean Six Sigma black belt courses. Choose SMART metrics (specific, measurable, achievable, relavent, and time based)
In the end, this article makes some good points, but I believe if you leave out the qualitative assessments of performance from the annual review, they must be provided more frequently in a different manner. To eliminate them would not be SMART decision