Cruel development

Although this device seems to be nice cheap, but could not keep up with my 430 EXII (original) in the flash quality for me.
Worst of all was the "fiepsen" which was heard even after switching off the device and apparently empty sucked the batteries. The next day they were empty already without great use. Alternatively, I have opened the battery cover after each turn, which interrupted the "fiepsen" and spared mE also the battery, but this is no permanent solution unacceptable!
I tried it with the firmware update on an old WinXP 32-bit PC. The installation of the update software is carried out only with a queasy feeling and is glad that it is carried out only on an old PC, which then not similar to online banking is used (virus ?!)
After updating the Yongnuo was no longer usable for me: sometimes he solved despite new batteries simply no longer sufficient and the contrast AF grid to support flickered repeatedly, even though the shutter button was not pressed! When the shutter button is pressed grid seemed also not constant to light but only from time to time .... USELESS! -> Immediate return