There is a significant difference. The signals from cabled/fibred cameras are uncompressed (apart from some light compression on recent Sony Digital Triax models, and there is some analogue noise introduced if earlier triax solutions are used - which still use analogue systems down the cable), and the compression used in EVS or similar servers, is pretty light (100-200Mbs intra), and the picture usually look very good indeed. As OLED production monitors appear in more and more trucks, the monitors are pretty amazing too. (Sony 17" and 24" OLEDs are appearing everywhere)
Satellite Backhauls are between 24 and 60Mbs MPEG2 (slightly lower bit rates used for H264 - 34Mbs H264 can look very good), whilst fibre can be uncompressed or high bitrate (~200Mbs) JPEG2000 or similar, or satellite equivalent bitrates and codecs can sometimes be used. You notice some compression artefacts if you look carefully.
Compared to the MPEG2 OTA I've seen whilst in the US - it's like night and day. The H264 compression used in Europe for HD is a bit better - but you still notice the differences.