Camino del Norte, about 800km, Camino Portugues about 600km (from Lissabon, 225 from Porto)
As peregrina2000 says Portugues is crowded starting from Porto.
Regarding 'touristic influence' from low to high: Portugues Lissabon to Porto, DelNorte/Primitivo variant, Del Norte, Portugues Porto to Santiago.
(and probably related are the number of Pilgrims!) I don't agree about the tourism influence on the Del Norte compared to the Portugues.
Portugues in mainly flat, Del Norte keeps going up and down, all the way! Del Norte is a more demanding camino! (Portugues the pleasure one ;-)
Del Norte is also called Ruta de la Costa, but often you see the sea, but cannot reach it as you're walking somewhat inland along cliffs, etc.
However, sometimes the Del Norte let's you walk with shoes in your hands and feet in the water!
Along first part of Del Norte are a few touristic cities, enjoy them or leave them.
The Primitivo variante from the Del Norte goes inland, no sea, nice nature.
Number of pilgrims depends on season, as usual more in the summer.
Brierley guide for Portugues! Not for Del Norte!
Portugues is mainly South-North through Portugal, Del Norte East-West through Spain (like CF).
Every Camino is different for each person, and even the same camino twice is different for the same person.
What a world to explore and experience!