We then worked out the climb gradient and the V2+40 case exceeded the V2+25 case
Minor point to note ... the use of V2 + 15, or thereabouts, does not reflect the maximum climb performance .. rather a reasonable compromise between better climb and worse takeoff distance ... the curve tends to be a bit flattish ... the absolute best climb is not of much use due to the need for half a continent's worth of runway to get to the requisite speed ...