Blu-ray doesn't look as good as in the stores

[hojh]

Hi, I have a Sony LCD 52 inch XBR2 and play my blu ray through my PS3 via a HDMI cable bought online. I was at Best Buy the other day and noticed on Sony 42 inch XBR4 that was playing pirates of the carribean the picture seemed so much clearer and "life-like" than my blu ray movies at home. Sales person told me the difference between mine at home and at the store was that my TV didn't have 120Hz refresh rate. I called Sony and they said my TV did have 120 so that shouldn't be the difference. Then another sales rep said it was because I wasn't using the Ultra Monster cables. I was skeptical and bought those but still didn't notice a difference at home(will be returning those cables later.) Now I have been hearing about how stores are using these demo discs that are all hyped up and not near the quality of normal blu rays. Is this possible? If this isn't likely, does anyone out there have any other thoughts as to why my home blu ray movies don't look as good as those I see at local stores? Thanks!