Really? Surely a pixel is a pixel though? You have a pre-determined amount of pixels with a resolution, so a touch over 2 million for 1080p. So then surely the biggest difference there when talking about different screen sizes then becomes it's pixel size, something that a smoothing of the edges is unlikely to overcome in reality.
The image on a panel is much, much brighter for a start. Everything looks clearer. Everything also looks more processed and a little unrealistic in comparison - I've yet to see an image on an LED, plasma or OLED that looks as natural as on a projector. As long as you can't see the pixel structure I find a pj image more forgiving, more film-like. More analogue. Can't explain it any better. Try sitting closer to a panel so the ratio of screen size to viewing distance is the same as with your pj and you might see what I mean.