LOL What an awesome demonstration of the average customer intelligence 
The only thing is there are very few places to go that actually have sets set up correctly to evaluate them 
Thats simple, you get the remotes to the TV's in Comet, bugger around with the settings on them all........then go and buy it online to save a few quid!
Not that I would ever do that 

That only works if they're showing a decent feed, though

Last time I was in John Lewis (in Laahndahn) they had all the 'big' HD sets at the back hooked up to the
worst feed I've ever seen; it purported to be HD but looked more like a bad NTSC composite signal (yet I could clearly see the HDMI cables!)..
Oddly enough the big Samsung LED sets they were obviously 'plugging' were hooked up to the same source, but displaying perfect clarity.
I could put it down to setup if it wasn't for the fact that all the other HD sets looked exactly the same (fuzzy and .. crap)
The 'small' (sub 32") sets were all displaying great feeds of the same thing, too.. really annoying, I wanted to see if the 63" Samsung was anywhere near as good as the 50" Panasonic..