It is hard to say without seeing for myself. All I can say is that going from my Sony 36'' SD CRT to my 50'' plasma via my 360 was
in every way. Of course some games are better than others and some flaws can be noticed from time to time, but nothing to write home about. But, I also do not sit 5 to 6 feet away when I play usually. I would have your HD/360 friends come over and take a look 1st hand and get thier opinions. See if they get a simular feel of what you are talking about. Don't tell them what you see first as that may force feed the issue with them. or go and hook up your 360 over at your friends place. Sharp and Samsung are 2 of the best LCD's in the biz IMO, so unless you have some serious setting/calibration issues, it may be you expectations as you stated.