User blog comment:Emptylord/Sandbox/Custom Patch Notes/@comment-1330314-20140324195326/@comment-3974211-20140324202334

Either I've worded my suggestion badly, or you've simply not thought it through.

I never proposed to give all champions the same mana regeneration. Even on a percentile system, the different between Ashe and Taric would exist. Give Ashe 0.5% Mana Regeneration and she will be fully regenerated after 200 seconds; and giving Taric 0.2% Mana Regeneration would mean he is fully regenerated after 500 seconds. Champions with small mana pools are not hurt by this system - I actually balanced the percentages around Vayne, who has the smallest mana pool at level 1.

So your second point is intentional. The point of my change was to make it so that mana regeneration provides a constant "effective time to fully regenerate". You purchase mana regeneration to reduce that time. If Ashe's "time to fully regenerate" is 200 seconds, then buying Muramana reduces it to 90 seconds. The numbers probably would need adjusting somewhat. Buying mana pool increases your up time - as you can cast more spells before you run out of mana.

The problem with the current system is that mana regeneration is negligible to the point of pointlessness unless you buy an extreme amount. Purchasing mana is about the only worthwhile way to increase your field-time.