the pitfall in comparing set in shop is

1. lighting is totally different from our house. unless the sets set up in special dark room.

2. the tv picture menu is 9/10 already tinkered with contracts set to maximum to achieve "clear" picture under shop's lighting.

my advise is to politely asked for the remote of each tv thats in your list. set it back to normal/standard/etc and compare again.

i have one experience where i asked for the remote and the salesman refused by saying sorry, no remote. he had a chore somewhere and went off, so while i was viewing the tv, saw the remote just above the blu ray. took it and press menu. contrast was full at 100. he saw me and came straight back so i said, i like tv and want to check a few things, its ok right?
he shrugged. next i said , hmm you set contrast at 100 ? thats standardlah..was his answer.

as anfieldude always said, its best to make an informed decision. thats including checking back what they are making you to see.

happy hunting.