Regarding upgrade effort, I would advise to consider the following :
- step 1 : upgrade the policy servers in mixed mode (no changes to the policy stores, iso features) keeping old admin UI and 1 older ps for admin purposes and all old agents.
- step 2 : after running for some time smoothly, upgrade the remaining policy server, policy stores and wamui and benefit of new features
- step 3 bvased on your needs, upgrade the agents.
agents are compatible with newer policy servers and only EOS when the underlying OS or web servers are EOS.
Step 1 should not represent a major upgrade work and regression testing versus updating all componenets at once.
12.5 has been announced EOS but not 12.51
Regards