At level 70 Lightning Shield orbs do 287damage. +15% would result in 330 damage. An increase of 43 damage per orb.
At level 70 Water Shield orbs give 204 mana. +15% would result in 234 mana. An increase of 30 mana per orb.
At level 70 Earth Shield orbs do 270 base healing(before +healing is factored in). +15% would result in 310 base healing done. An increase of 40 base healing per orb.
At level 80 Lightning Shield orbs do 380 damage. +15% would result in 437 damage. An increase of 57 damage per orb.
At level 80 Earth Shield orbs do 337 base healing(before +spell power is factored in). +15% would result in 387.55 base healing done. An increase of 50.55 base healing per orb.
My Earth Shield orbs(with 2300 +healing) heal for 1021. +15% would result in 1174 healing done. An increase of 153 healing per orb.