Mana Items Are At There Worst When You Want Them The Most
All the % Base Mana Regen items are at their worst on champions with bad mana regen and at lower lvls where mana regen is worse. Just think about that for a moment...
Now can we get more real flat regen options again please? Even d-ring, the mana font passive, and 3 points in meditation don't keep me from running out of mana very easily despite trying to conserve it very hard. Meanwhile manaless champions spam away as if the world will end if they stop hitting Q...
get to spam regardless
which happened.
and
who do expend a lot of there mana pool over time and heavily benefit from missing mana. The item serves its purpose well. I don't any risk or reward play is involved with its other passive, It is more for team fights or giving a mage some mana in case of trying to escape after a fight.

keeping them sustained.
and
had to do was buy
, whats mana?" While it is true that some of the manaless champions might be on the easier to play/stronger side, there wouldn't be a way to tone them down without removing endless mana for other champions.