As i sad, these are OK ESC's. If you wanna use them with multirotors, you wanna flash them with simonk's firmware, and make a few modifications on them. Download the source code and edit tgy.inc file. Change .equ F_CPU = 16000000 to .equ F_CPU = 8000000. This ESC's have Atmega8L-8AU which will work on 8 MHz, forget about 16 MHz. Compile the source code with avra.exe, if you are on windows. There is a little bat file on the internet which will help you with that. After compiling, rip of the shrink tube from ESC. Carefully solder some thin wires on the chip, or you can use the flashing tool which can be bought one some other popular site. Add external crystal oscillator to xtal1 and xtal2 pins - 8 MHz with 2x 15 pF to Ground. Look into datasheet for more info. Leads from crystal can be a little longer. We are on 8 Mhz only. After soldering external crystal, you must enable it. Use eXtreme AVR burner for that. Launch the program, configure your programmer. Select Fuse Bits/Settings tab. Down on the left side there is Configure AVR clock icon. Select External Crystal/Ceramic Resonator, frequency range 3.0-8.0 MHz. I had selected Startup time 258CK, i don't know if it makes any difference with other settings. For oscillator option select Limited Swing (for xtal in range 1-8 MHz). Confirm your settings. Select write on low and high fuse. And finally, write fuses on the micro controller. If all goes well, you should have external oscillator running on atmega - at 8MHz. This is now very imune to temperature changes. You ESC will work like a charm. No more weird noises from motors. And don't forget to put some new heat shrink tube on the ESC. Enjoy!

Finally i flashed this XXD HW30A 30A Brushless Motor ESC to SimonK firmware to run on my Hexacopter, this XXD HW30A 30A Brushless Motor ESC work very well after flashed SimonK firmware.