This dilemma has been discussed on here many times - I'm sure you'd find it interesting to search the archives. ÿFor what it's worth, I looked very closely at all the excellent Panasonics (HD Ready and Full HD) and also had a good look at the Sony when it first came out. ÿIn the end, I decided to see what all the fuss was about over the Pioneer Kuros and was so impressed that I pushed the boat out on one of the last remaining 4280s (basically the same set as the one you're considering).
ÿIn the end, the quality of SD picture was an important factor. ÿAt present, most of the films I want to watch are only on DVD and some of my favourite programmes are not broadcast in HD. ÿBroadcast HD material isn't Full HD anyway. ÿWhen I did my Freeview/SD/DVD playback research, all of the HD Ready sets were superior to the Full HD. ÿIMHO, the Sony looked brilliant on BluRay, but there was just too much 'fuzz' on SD and it was the worst of all on my shortlist. ÿContrary to what you fear, you will see the most 'liney' picture on this set. ÿ
ÿI am now enjoying my Pioneerÿ- viewing distance about the same as you. ÿI'm glad I went for a 42" screen instead of the Panasonic 37PX80 I'd been intending to buy, but I wouldn't want to sit any closer. ÿUpscaled DVD looks far better than I'd hoped for (I'm letting the panel do all the upscaling) and Sky SD is quite watchable. ÿNevertheless, I'm thrilled with the quality of HD programmes - the Olympics looks staggering. ÿAlthough it's not really my thing, the kids enjoy Gladiators and it's the best PQ of all. ÿI don't regret going for HD Ready (768p) at all. ÿI'm afraid I've been seduced by those legendary deep blacks of the Kuro!
ÿIf you look on other forums, you'll find details of the Pioneer set-up - a great help. ÿI did discover that choosing the alternative DRE and EnhancerÿMode settings and having 0 sharpness made a big difference. ÿIt does go to show that, in addition to the differences between sets, it's possible to change the PQ on any one set by changing the parameters (see the Philips test on the main page).