Problems with VBFA table (transparent or cluster???)

Hello,

We are right now running the upgrade process from SAP R/3 46C to SAP ERP 6.0

We've found out that the VBFA table has changed from transparent to cluster.

The thing is that we have created some alternative index on this table, and it's used on custom views and queries, wich is no longer possible.

According to the SAP Note 121799, it's possible to keep this table as transparent, but I really don't know if it's the must convenient to do.

Does anyone has face the same problem??

are there alternate index tables for VBFA, that allow a better performance when searching on them?

Thank you