SD-DVD - 720 x 480
VHS - 320 x 240
The difference in quality between HD-DVD and SD-DVD is huge. Even greater then the difference between DVD and VHS. HD-DVD has twice the resolution of D-VHS, 3x the resolution of HDTV, and 6x the resolution of SD-DVD. The worst looking HD-DVD will be alot better then the best looking SD-DVD. To say that the picture quality won't be much better must come from a person who has never seen a D-VHS movie on a good HDTV. Its amazing. Also unlike Sonys junk HD-DVD can be manufactored with the same assembly lines as current DVDs. With that HD-DVD will be very cheap. Laserdisc and D-VHS were both niche formats because they offered higher quality at the expense of cost and convience. HD-DVD offers much much better quality with all the cheap cost and convience.