720p looks about like a good 35 mm print in a movie theater. 1080p sourced from Blu-ray to a 1080p display looks like a clean window onto the real thing.
720p IS NOT the same thing as 1080i. 1080i actually has 1080 discrete lines of resolution; it's just that it takes two 60Hz cycles to see them all. Still, you're getting a display of 2,076,300 pixels. A 1080p display upconverts 1080i to 1080p and you really get 1080 lines of resolution. Although a native 720p LCD/DLP/Plasma display can accept 1080i input, it downconverts it to 720p, which gives you 921,600 pixels.
In the case of a front projector, I would think that a 7 foot screen would show a dramatic increase in sharpness with a 1080p projector over 720p, especially when sourced from either 1080i broadcast or especially 1080p Blu-ray. Once you experience 1080p from source to display, you'll never want to return to anything less.
720p IS NOT the same thing as 1080i. 1080i actually has 1080 discrete lines of resolution; it's just that it takes two 60Hz cycles to see them all. Still, you're getting a display of 2,076,300 pixels. A 1080p display upconverts 1080i to 1080p and you really get 1080 lines of resolution. Although a native 720p LCD/DLP/Plasma display can accept 1080i input, it downconverts it to 720p, which gives you 921,600 pixels.
In the case of a front projector, I would think that a 7 foot screen would show a dramatic increase in sharpness with a 1080p projector over 720p, especially when sourced from either 1080i broadcast or especially 1080p Blu-ray. Once you experience 1080p from source to display, you'll never want to return to anything less.