Share ur experience:lessons learnt from a SAP technical upgrade4.6c to 6.0

Dear all,

I am working for a SAP Technical upgrade project (upgrade from 4.6c to ECC 6.0).

I am involved in improving a document on 'Lessons Learnt from SAP Technical Upgrade'.

Hence, please share your experience on upgrade from 4.6c to 6.0 (ie. things learnt from SAP tech upgrade).

If i am not lucid, please let me know. Will try to put my query in a different way.

Thanks all of you in advance.