Inverter and/or electric troubleshooting help needed

ISTR somebody here has one of those?

http://www.wegosolar.com/products.php?product=KI%252dSW2012%252d55-2000W-12VDC-Pure-Sine-Wave-Inverter-with-55A-Battery-Charger-

These guys usually don't sell junk, so I am surprised at the bad reviews on that other one. Maybe it is just too complicated for folks.

Is it LY who has that neighbour he helps who refuses to do things right? Full marks for helping those people out. Could be an endless task it seems. You will have to move away to be free! :(