I recently picked up a Hobbywing Skywalker 40A ESC to test out. Several folks on the RC Powers forum use this with good success, so I thought I would order one and give it a try. I picked mine up from this vendor on Ebay for $11.39 USD. Shipping was free, but took awhile, 29 days from time of shipping until it was in my mail box.
The instruction manual looks very similar to the one that comes with the Turnigy Plush ESCs I have purchased in the past.
I had to search around a bit to find some specs, the Hobbywing website was of very little use to me unfortunately. I did find some specs from a different Ebay vendor here. The ESC with connector weighs 48 gr/1.7 oz, so it is about 7 gr heavier than the Turnigy Plush and RC Timer 40A ESCs I have tested in the past and still use in my planes. It is rated to 55A for a 10 second burst which is the same as the Turnigy Plush ESC and more than the RC Timer ESC. The BEC is the same as the RC Timer ESC at 3V/5A, the Turnigy Plush is 5V/5A.
The Hobbywing ESC is programmable using either the Turnigy ESC or Hobbywing ESC programming cards.
To set the throttle points, it is the same as the Turnigy Plush, turn on the transmitter, put the throttle to 100%, connect the battery, you get a few beeps, then two solid beeps, reduce the throttle to zero and the ESC finishes arming. The RC Timer 40A ESC has the same arming process, but the sequence of beeps initially is a little different which you can read about here.
For now I have it installed in one of my planes with a lower amp draw setup and will test it for awhile before moving up to more powerful, higher amp draw motors to see how it does handling six servos and dissipating heat as the amp draw of the motors gets closer to 40A with the "medium" and "hot" setups I have in a couple of my planes.