Hi,
IMO a Full HD TV will serve it's purpose only if you use it to watch contents of resolution 1920/1080, i.e a 1080p content. Anything less than this resolution is going to be upscaled through your Amp/DVDp etc. And upscaling is only going to blow up your image to any resolution but without any detail. The resulting image is not going to be as crisp as a 1080p image, and ultimately there is no fun in viewing such images. And even the color outputed by an Full HD TV is far more precise compared to that of a HD Ready TV.
FYI, there is no technology that can upscale a DVD content to Full HD content, i.e Bluray such that there is 100% accuracy in visual details and color. You can never get the details of a 1080p in an upscaled content. Make a note of this fact.
I'll give you an eg:- I think everybody knows about this famous Chinese(Mandarin) movie HERO(Ying xiong). There is a sequence in that movie where Flying Snow and Moon are fighting in the forest and Moon chops off a clump of hair from Flying Snow's head.
Ok, this sequence when you see it on a DVD+HD ready TV, you cannot see a single detail in that hair clump which gets cut off. Even if you use a DVD+Full HD TV, no details, even Bluray+HD ready gives no detail.......but in the combo of Bluray+Full HD (both 1080p) each and every strand's of the hair in that clump is visible. And since i'm from the VFX/Animation industry I deal with these resolutions on a day to day basis and I can surely make out a difference in them. But do not know about other's.
Another eg. is the details on Heath Ledgers hair and it color in the movie The Dark Night, there is a phenomenal difference with a dvd version and a bluray version.
One factor which help's in bringing out these details is the Black/White Levels offered by any particular medium, which lack's in a HD Ready TV's.
And whenever you go to demo a FULL HD TV, look for these, first of all no dealer in India plays true HD contents when demoing a FULL HD TV, and at sometimes in these AV exhibition's they do play HD stuff's but they are all colorful and bright. Ask them to play something which has been shot against a black background. And when you view this sample, the black background should look "BLACK", i.e you should not be able to differentiate between the black background and the black border of the TV. If you make out the difference, then that particular medium is not suited for FULL HD content. The LED's from Sony and Samsung have a very good B/W level's compared to their LCD's.
And at the end of all these, no TV/Projector can produce B/W levels with 100% accuracy.
So, at the end of the day I prefer BLURAY + FULL HD 1080p combo. It "RULES"
Hope this helped, and any opinion regarding the same from other's.
cheers