Calibrating Appraisal Ratings

Hi,

Looking for some help on configuring Appraisal Calibration/Talent Review Meeting, as per my understanding calibration functionality is available both in BSP (EHP5 and below) and WD ABAP (EHP6).

We are on EHP5 and planning to upgrade it to EHP6 or still we can go for calibration in EHP5, would it be good to go with  WD ABAP after Upgrade. Please share your thoughts.

As we have standard 9 grid functionality with Performance and Potential, can we only configure Performance grid without Potential, can we drag and drop the participants with in the performance Grid. I came across one Badi which can be used

http://help.sap.com/erp2005_ehp_06/helpdata/en/83/8434f4e7b6422c8770977a6434a67f/content.htm?frameset=/en/3f/6efcf555334d9e981c36e253dc2aec/frameset.htm&current_toc=/en/73/d39f69582141f792996559398c03d4/plain.htm&node_id=57&show_children=false

Can bell curve (graphical view of calibrated documents) view also delivered in standard?  Please share your experiences on Appraisal Calibration .

Thanks

Rag