Stoneborne Pact is a let down

I tried out Stoneborne Pact in a test game and it was sad how useless it was compared to Bond of Stone. Even if you play as Sion and build Hp then get 3000 hp all this rune does is heal someone about 80hp....... 40 if they are ranged.

When you consider that a tank over a long game can take around 40k of damage, 4% damage reduction is like 1600 health. Stone borne pact just gives 5% hp at best this is 150 hp if you build up to 3000 hp. that is a loss of 1450 effective hp.

This keystone is basicaly useless. If it healed a ranged ADC for 220 then we are approaching usefull IMO....