Would you consider having fewer PVs, or just a single one for each donor rank? This would help raiding and encourage people to have claimed vaults rather than hiding things away in PVs.
I feel like it would bring back more of the original intentions of the faction gamemode, however I also think this will upset people that are attached to their vaults and make them feel as if they got 'ripped off'. So perhaps those donators get something else to replace their PVs.
I say each one should be cut by 50%. all ranks with 1 pv have 1, all with 2 have 1, all with 3 have 2, all with 4 have 2, all with 5 have 3, all with 6 have 3.