Hobbywing just released some versions of the ESC for multirotors.
Xrotor PRO 40A, Xrotor 40A PRO 3D and Xrotor 10A Mini 3s.

The Xrotor 10A mini 3S is good for the 250 FPV racers.

For Xrotor PRO 40A:

Features :
Special core program for multi-rotor controllers greatly improves throttle response.
Auto Timing Adjustment and Preset Parameters for easy operation.
DEO (Driving Efficiency Optimization) technology significantly improves throttle linearity and driving efficiency.
Open Cooling Fin.

Specification :
Output : Continuous 40A, Burst 60A up to 10 seconds
Input Voltage : 3-6cells lithium battery
BEC : NO BEC
Refresh rate of the throttle signal : up to 621Hz
Timing : High or Intermediate
Red Black cable length : 475mm
Signal cable length : 560mm
Bullet Connector : 3.5mm
Size : 73.5 x 23 x 11mm
Weight : 45g

For Xrotor PRO 40A 3D, it has 3D function:
ESCs can make multirotor do 3D flight via switch rapidly from driving the motor from running CW to CCW. Motors run CW in the area ranges from 51% to 100% throttle, run CCW in the area ranges from 0% to 49% throttle. The dead band ranges from 49% to 51% throttle, 50% is the neutral position.