Soul gems in oblivion are much rarer (or seem to be) than in Skyrim and weapons in Oblivion have, for the most part, larger enchantment point pools.
It doesn't seem fair that Oblivion soul gems only restore about half of what Skyrim soul gems do. This mod fixes that.

This mod changes Oblivion's soul gems to have equal capacities to Skyrim's.

Petty gems can store 250 now instead of 150.
Lesser gems can store 500 now instead of 300.
Common gems can store 1000 now instead of 800.
Greater gems can store 2000 now instead of 1200.
Grand gems can store 3000 now instead of 1600.

This doesn't change the gems themselves, but the game settings that determine the size of souls.
So, this is compatible with any soul gem mod granted that it doesn't change these settings.

A side effect of this mod is that enchanted weapons made at altars have greatly increased numbers of charges which you may feel is a bit unbalanced.