rags,
Its an eye contrast issue rather than anything with the sets. If your tv is surrounded in darkness, your pupils open up wide and catch even the smallest amounts of light. So the poor blacks on an LCD set really show up badly as a kind of dark blue/gray colour.
As a general rule, its not a good thing when the area around the TV is darker than the blacks on the TV. This is an LCD killer.
However, in a well lit room, where the TVs surrounding room is much brighter, this creates a nice high contrast between the light in the room and the blacks on the TV. Your eyes will see blacks as true blacks in this case.
Using my samsung LCD rptv during the day, in a very well lit room, looks bloody amazing. Just like your example of the sony in a bright room.
close the curtains and switch off the lights, and it looks awfull. I actually place a light behind and above my TV. This helps greatly in the evening. Without it, its washed-out. But with the light on, my 'internal' contrast improves greatly.
Personally, I dont care. I HATE watching tvs in dark room, so I wanted a tv that looks great in very well lit rooms. For me LCD was the best option. A tv with 'better blacks' would make my eyes crush all the dark detail in daylight. The LCD simply looks perfect.