I purchased this so I could shelve the component cables and hook up everything via HDMI going forward.
I imagine most people buying this are probably coming from the composite video cables (yellow, white, red). By using this converter, the image quality should see a noticeable improvement.
This device is more a converter than a scaler. This is how it works: This device plugs into the A/V port on the back of the Wii. The device taps into the component video output of the A/V port, which is the highest quality the Wii outputs. The device performs a analog-to-digital conversion and outputs the digital signal via HDMI, 720x480@60Hz (EDTV 480p). This device does nothing to "upscale" or improve the image, it simply converts the 480p analog component signal to a 480p digital HDMI output. This is actually ideal, because an upscale would degrade image quality further. The analog stereo audio is converted to Linear-PCM 16-bit 48KHz, which is very high-quality and compatible. The digital audio/video signal is sent over a connected HDMI cable to a monitor or television.
After setting up the device, make sure to enter your Wii Settings and change the aspect ratio (Widescreen Settings) to 16:9 (if using a widescreen display or an HDTV), the Resolution to 480p (EDTV) (if your display supports this, all HDTVs do), and the Surround Sound Settings to Surround (Dolby Pro Logic II) for the best video and audio quality. Adjust your television to stretch the newly configured widescreen video across the screen (if using a widescreen display). Finally, if using a surround sound system, engage Dolby Pro Logic II decoding for surround effect in supported games.
This device does work decently, however there are some problems: The device adds input latency (lag). This is somewhere in the realm of 2-3 frames I'm thinking, but I actually haven't measured it. This device adds dancing diagonal interference into the video signal. It's most visible on bold solid colors and gradients like red. If you're sitting several feet away, I doubt you'll see it however. Some televisions might completely mask the interference, anyway.
In terms of convenience and ease-of-use, this thing is pretty neat. Having everything in an A/V setup working on HDMI is much more convenient. However, the video quality is not as good as it could be.
EDIT 12/17/2018: The adapter has died and I am now getting a free replacement. I would definitely question the quality control of manufacturing these.