What are the real Performance Management trends in the Middle East? Any company enforcing a 360 degree performance appraisal system?

a feedback system degree 360 at an advanced stage to find out all possible information on the level of performance ..It is based on several sources of assessment so they are not limited to the evaluation process only presidents ...
Presidents - colleagues - subordinates - Clients

Actually, my company used performance related appraisal.
Yet periodically we conduct 360 degree appraisal in case required.
We apply it in case there is a controversy regarding the performance of a particular employee; either some argue that he/she is not performing well while other are satisfied by the performance.
Or the employee is not satisfied by his supervisor's appraisal and claim bias.
In such situations we conduct 360 degree appraisal through which we engage all the head of departments with whom this employee has been engaged by work.
If he deal with customers, we send to key customers to get satisfaction survey and evaluate the results.
We consolidate these appraisals and prepare scorecard through which we have the final results of the appraisal.

Thanks for your response.
Just wanted to clarify few points.
How do u feel the 360 PA useful for recording unbiases appraisal? Dont you feel it hard to apply on a large scale organization? What the parameters your organization takes to record the transparent PA?