The 2010 Pannys are not as good as the 09s or the LD450 in terms of input lag or PC use. But in terms of overall picture quality it blows the LG away, and is a little better then the 09 Pannys.
So for PC use the 09 Pannys and the LD450 would rank about a 10.
For PQ, the 09 Pannys would be about 8, the 10 Pannys about 9, and the LD450 about 5.
To me the drastic PQ difference is more then enough to sacrafice 4:4:4 and .5 frame delay. At the very most you are looking at 2 frames on the U22s, which no one would ever never notice anyway. The text could be better yes, but its still better then most, and more then usable daily.
Ive compaired the Sammy C550, LD350/400/450, Panny U22/C22s, and the Insignia equivelent. The Sammy had the best picture quality, but not that far ahead of the Pannys. The Insignia came after the Pannys but still ahead of the LG.
Ive had a lot of expeirance setting up TVs (not with proffesional equipment, but still use lagom and different free stuff thats around) and there is nothing at all I can do to the LG to give a picture thats close to good. I got it cheap, and gave it to my GF for 360 use, so I dont care really. But if it were for me, Id never get it.
I am surprised the Insig faired so well in your tests... I was looking at that cheaper one as well and decided not to because of the brand name and PQ obviously The Panasonic seemed so much more for about the same price since you'd have to pay taxes and such at Worst Buy