The following two images have are screen shots from Mediaportal.
The first image is Freeview DVB-T TVNZ Sports Extra which is broadcast in standard def.
The second image is Freeview DVB-T Tv One which is broadcast in HD Ready def.
The difference in the colours and the depth/quality of the picture is quite amazing.
No need for all the marketing hype this is the real user test showing the very clear difference.