I just installed a ZTW Mantis Series 35A ESC in my E-Cavalier. It has a quirk that gave me a fright till I figured out what was going on. After a test run the Cobra motor did not want to freewheel. I felt like something had gone wrong with the motor. I was about to remove the motor and unassailable it to find out what was binding. I was interrupted and left the shop for a while. When I came back the motor was OK. It freewheeled as it should. I inserted an amp meter and did another test run. Current was normal. Turned the motor off and it was frozen up again. I sat around scratching my head and flipping the prop. The longer I waited the freer the motor became. To make a long story short The ZTW ESC holds a charge for a long time after you disconnect the battery. It is acting as an electronic brake.
Outside of this non-problem the ZTW Mantis works well with my KR timer. I bought the program card, $9.00. It works great. One feature of the ZTW Mantus, that I like, it has programmable reverse motor rotation. I had all of the wires tied up and tucked away when I discovered that the rotation direction was wrong. Took about a minute to fix. This feature could also be useful to experiment between tractor and pusher props. Anyway the ZTW Mantis looks like a good match for the KR Timer.