Brushless Savage Setup

Thanks for Input. One last question (I hope...):

Let's stay with this two setups:
a) BK 20XL/7 (kv: 2145, about 95 amps)
b) BK 20L/10 (kv: 2212, about 60 amps)

KV and so top speed is nearly equal. What about the run time?

Does the 10L really has a noticeable longer run time because of the less amps? Or does the more torque of the 7XL is balancing this?
Does the 10L is more kindly to the drive train while accelerating?

Thanks again
-- Dave