Why is upgrading the ODS important?

I search for information about upgrading ODS to a new version to support a Domino migration  and justify the upgrade of the ODS.

The summary is bellow.

On-Disk Structure (ODS)

Every major release of Notes/Domino (e.g., versions 2, 3, 4, 5, 6/7 ,8 and 8.5 ) has included significant architectural changes to the database structure, also known as the On-Disk Structure (ODS). These architectural changes enables the Notes and Domino development team to improve performance and scalability in each release. Upgrading the databases provides a lot of benefits, with very low risk, so this has always been an important early step in any Notes and Domino upgrade plan.

The ODS version for each major release of Notes and Domino is as follows:
  • v2 -- ODS 16/16.3
  • v3 -- ODS 17/17.3
  • v4 -- ODS 20
  • v5 -- ODS 41
  • v6/v7 -- ODS 43
  • v8 -- ODS 48
  • v8.5 -- ODS 51