Some people really should understand that this is not at all what I said. For clarity, not that it really matters, but...
The converter accepts composite and s-vid and outputs VGA (higher freq RGBHV) either 640x420 or 800x600 (menu selectable). That's one improvement, scaling up to a higher resolution. The signal is taken from the system/source and put into the selected VGA format. My box has options that filter signal noise and normalize the input signal with other filtering. You do still get some telltale composite artifacts, but the processes nearly eliminates the most horrid and noticeable instances of color bleed/rainbow artifacts and to a lesser extent, dot crawl. Considering what the NES RGB mod requires (and also the downsides like the messed up color palette), I'm satisfied with the level of quality this method produces.
The Megaviews were produced mid to late 90's, so IDK what, if any, filtering process they'd have on the composite and s-vid inputs to itself. Since it was designed as a broadcast/reference monitor, I somewhat doubt it would employ them since you'd want to see the actual quality of what you are looking at unprocessed, ideally. They are not your usual RGB monitor. They can handle a wide range of inputs on the 5BNC RGB inputs, and the set hardware scans, auto-detects and configures to the input. RGBs, RGBHV, RGsB, VGA... Auto-scans the freq range too. They're wonder displays, at least I'm very impressed with them.
You should have seen the set-up where I played 2600 and TG16 through RF into my DVD recorder, getting s-vid output, and putting that into the converter box and then the VGA into a computer monitor... Frankengaming 101.