need some advice on new tv

i currently own a 42 pioneer pdp 4270xd i was wanting to upgrade to a panasonic tx p50vt30 but when i went to get one the guy told me i  would not see much differance in quality? anyone advice me on what to do or can anyone advice on a screen 50inch budget 1500 i only use it for viewing bluerays and am not that bothered about 3d. thanks maka,