I have had both pre and post 64 guns. I don't agree that the difference is hype. Also, in the 60's, Winchester had one model, there was not a "delux" walnut" model.
Onr of the diiferences is the cartidge lifter, pre 64 guns had forged, milled steel, the post 64 guns had stamped sheet metal. Some guys had no problem with the stamped ones, but many did. They tend to wear faster, and can bend. Replacing them is easy tho. Winchester went back to the forged lifter after having trouble with the stamped ones.
Loading gates on many of the post guns were not finished well, with poor fitting of the gate as it was folded and formed. This is also easy to replace with a newer, better made part.
The checkered butt plates on the older guns were true raised checkering, the later guns had stamped, impressed "reverse" checkering. Better than the later plastic butt plates, but not as well made or looking as the pre 64 guns.
The receivers of post 64 guns were cast, and the blue wore differently, and is very tough to refinish well. They usually turn purple when re-blued. This was corrected later, in about 1982 I believe, they went back to forged recievers. Receivers on post 64 guns also had very square lower edges, amaking them less comfortable to carry. Earlier guns were nicely beveled on the lower edge, with guns back in the 20's and earlier being even more beveled than later pre-64's. The older guns are very nice feeling in the hand when carrying.
The post 64 guns are fine guns, and work well, are often capable of very good accuracy, but they just weren't made as well as earlier guns. As far as that goes, the Winchesters made up to through the change to short forends and ramp sights were even finer made than the late pre-64 guns. It has been a long slide away from a work of art to a production line product that doesn't seen to have as much character for many of us.
I'd still take a modern Winchester over any other make, some newer guns I've seen were very slick operating, but I just like the earlier guns much better.