The wii doesn't have 1080p scaling native to it. And this device doesn't just magically allow you to have 1080p scaling because it plugs in. I have to expand the image on the TV to widescreen to get rid of the edges. So it is not in fact 1080p. It's an upscaled 480p, and a bad one. While this is better than a square picture for me that is native to the wii, this item is not a 1080/720p device just an upscaler.
It's better than 480p, but it's noticeable scaling issues; edges of lines are badly pixelated, colors bleeds and slight artifacting occur.
So not only is the 480p a 4:3 resolution and this device upscales to a 1080p/720p 4:3 not the modern standard 16:9, so you have boxy issues with this regardless.
It IS an improvement over 480p 4:3. But only marginally.