i would say different showrooms/shops demonstrate/set their products differently. under normal circumstances the higher margin one the better. so you can't really compare them unbiasly.
as a plasma user, why not the panasonic 55vt60? i have a 50vt30 in the bedroom and a 65vt60 in the living room, both are far better than my previous sony ??40??4500 from my point of view
by the way,
go for the biggest you can afford (locationwise and budgetwise).
i moved from sony crt 29" to sony lcd 32" and said "big enough". from the 32" to sony 40" and said " wow, better", from 40" to panasonic 50" said "best suit my living room". before i bought the pana 65" i said "i regret that i didn't go for the 60""!