Classical PCA vs new GL in HANA Reporting

Dear Experts,

I have seen several posts but I have full confusion about PCA.

What is basic customization difference between Classical pca and New GL, As per my understanding, In 0KE5, If we check that it would be classical, And 1KEK is pure classical one. But If I checked for profit center, zero balance in document splitting characteristic for gl, I don't tick in 0KE5 it is giving error. so I was forced to activate this in 0KE5 also.

Please explain for each check mark importance with different scenarios. and also let me know the new reports in New gl with respect to classical. how can we get different reports in New gl.

let me have some good links regarding this topic.

Let me know for further info.

Thanks,

Ashok