Well it seems low in rating, but however, I have been using a AXI 5330 with a 20x13 AXI prop which have a consumption of 67A @10S, the SPARK is rated to be used with around 2kW so the 57A @10S seems fair enough.
Be aware that this motor have a 5:1 gearbox giving you 170kv on the shaft, that's why they recommend prop's in the high region as 22x12.
I have flown the KRILL SPARK now from the beginning of it release I even have a prototype version of it and IT IS NOT designed for high speed, try have a look at KRILL's webpage and you will notice that the motors recommed ALL is in the 170kv range and NOT the useual 230kv , it is very very stable in high wind even with low speed. But off course I'm a bit nervous if the MEGA have enough power, I might go for a even bigger prop as a 23x12 or 22x14 only time will show.

Joen