My Panasonic plasma displays at 1080/24, when playing blu ray discs, and one or other of the two you mentioned when playing SD, Sandra. Have to admit, I'd always thought it was something to do with PAL / NTSC, but I could be wrong.
You are right about the NTSC/PAL thing I think Simon.
I did some more reading about OLED and laser TVs after I posted and one of the articles contained something that I think partially clears these things up.
P or progressive displays run at 24 frames per second on PAL displays and 30 frames per second on NTSC. i or interlaced displays are doubled to 48 and 60 frames per seconds respectively. So I assume that my TV is 50 fps as its PAL (probably easier than doing 48 for some reason) and not 60 as it would be if it was NTSC.
David, you will definately notice a difference between HD and SD and the difference is more pronounced on bigger screen sizes. The problem is only really on the SD side of things as both LCD and Plasma will show HD content brilliantly, even on cheaper panels, I would think black levels and contrast ratios would be the only real difference between cheaper and dearer sets.
However you can not get as good a picture from an SD source, upscaling it may help but that can introduce problems with the picture apparently, as you can from a CRT. You have seen that already with your own CRT and LCD pictures.
I always think that its funny that people used to spend a fortune on audio equipment because they could listen to it and some people could detect that one system was better than the other yet those same people will now go and buy a Plasma or LCD because it looks nice when its off and showing HD but dont seem to care what it looks like when showing SD content
@Clive, there is a vast difference in HD, mine looks almost 3D on some type of programmes. I think you must have it set wrong . Try swapping the settings from 720p to 1080i or vice versa.
720p is supposedly better for fast action and sports, 1080i for general and movies. If you have a 1080p panel and source then thats the best for everything