Note: I bought the Muntaha Tech one which was really cheap so the awfulness was expected and this isn't necessarily the case for ones sold by others.
First impressions - it was all black except for the composite video connector. Both the cables coming out of the VGA plug were the same thickness. Similar to the one in the picture.
Then it turns bad - when plugged into any of my laptops they won't boot and if the adaptor is plugged in while the laptop is on then it turns off immediately. Both test TVs (composite video) show a jumpy blank image (the bit that shows what channel it is on jumping around).
When plugged into a desktop computer's dedicated graphics card, the computer turns on etc. but I don't know if the graphics card turns itself off or not because with the adaptor connected I can't connect a monitor since the monitor is also VGA but that isn't the fault of the adaptor. Again, a jumpy blank image on the TV.
I read another review which claims that someone got this adaptor to show video output from a N64 on a VGA computer monitor. After plugging the adaptor into the monitor, it said 'Check cable' as if no cable was attached at all.
When testing with a multimeter, pin 9 and pin 10 are shorted so that's 5V and GND shorted together which explains why none of the laptops would turn on. Also, the outside connection on the composite video connector wasn't connected to anything at all and the inside one was connected to GND so therefore the composite video connector is useless. The GND pins on the S-video connector were both connected to the metal shell of the connector and nothing else. And of course, the S-video connector didn't work in any computer, even after I pulled out the 5V pin (pin 9) to remove the short, after which the laptops would actually turn on making the short the culprit initially.
The graphics card in the desktop computer is a NVIDIA GeForce 9500GT, which is available with VGA, HDMI and DVI or VGA, S-Video and DVI so I was expecting the S-Video on the adaptor to work since if the HDMI replaces the S-video on the card, then the S-video could have been moved to the VGA port.
But of course, with the adaptor so badly and incompetently designed, wired and manufactured, by people who have obviously never obtained any sort of electronics or computing qualification, I doubt it would have worked with a card that's guaranteed to have TV-out on the VGA port. And many modern integrated graphics drivers (such as Intel's), insist on the output device giving it some indication of its presence anyway, which wasn't present.