Interlacing is absolutely gross. It's an old technique used to reduce GPU load first appeared in midtown madness 1 in software mode if I recall correctly. This was 1999. I have also tried this interlacing in resident evil ( I think the first person one?) It was as I expected. When you are interlacing, the image looks as if half of the pixels are black while other half are showing what is supposed to be shown.
@Necrokiller if somebody is saying they are NOT noticing the difference, be assured they either: need a trip to the ophthalmologist, or are in denial. Or you know, they could be lying.