Till recently, I have used an old 32"Panasonic CRT TV on Virgin media cable (SD)box, and found the picture quality''very acceptable'.
I have now bought a Samsung UE37EH5000, and unsurprisingly the picture quality ranges from poor to acceptable~this is supposed to have Freesat HD, but this presumably is not routed through the VM box.
The answer to this seems to be to get a VM HD box, and I will then enjoy fabulous HD quality.....?!, or are there any other considerations??