Anyone go from 42" 1080I to 46" 1080p?

[sudbury78]

I was all set to buy myself a samsung 46 inch lcd and two stores, one of which has their employees work on commission told me I would be wasting my money because I wont see a drastic difference in picture. My 42inch is a 4 year rear projection lcd and I figure even without blu-ray, a typical HD broadcast would look better. I am so dissapointed, because I certainly dont want to waste 2500 bucks if I wont see a difference. He, like many people, say the only true difference to the naked eye is on a 50" and up.

Do you all agree?