If you will look at the original 512 with no sharpness (circled in point A you will see a tad bit of bluriness, its small and hard to notice but if look closely you can see the fogginess of texture.
If you look at point B you can see the sharpen feature has caused the pixels to cause small dots along the seam (ripping)
If you look at point C it has good texture with no ripping and strong reflection on it as well. The fogginess is minimal and the details are more encased into the box becuase when you shrink 1024 you have more room to work with detail that is shrunk down into 512.
I wish you would have put more light on the 1024 boxes so i can point the detail a lil more, they are in the shadows of the pic...
Those who fly low hurt least when they fall...