Pre and cons :
what you want
if you like the ocean then the Coastal will be your path.
untill Redondela there are hardly any climbs except for the “mountain “ that you see for miles before entering Caminha and you will climb after leaving A Guarda at the Spanish side of the Minho river.
you can leave the coastal and connect with the Central route at Vila do Conde or at Caminha. Cons of the coastal. It can be windy… the boardwalk will be used by pilgrims but also by joggers and bikers so you have to take care they do not hit you. You can loose your rubber tips of your poles between the wooden planks of the boardwalks.
the Central route. Untill Maia (about 12 kms from the Porto Cathedral) I I do not advise to use the waymarked road out of Porto if you do not like crossing busy roads with heavy traffic and walking on the hardshoulder, the traffic passing you less than 1 meter from you. After Maia there is still roadwalking but after Vairão ( stay at albergue Mosteiro de Vairão very nice place) and Vilarinho starts a more rural path towards São Pedro de Rates. There is some more roadwalking around Pedra Furada and Barcelos.
Between Barcelos and Ponte de Lima is the most famous albergue of the entire Caminho Português,
Casa da Fernanda in Vitorino dos Piães - reservation on beforehand advised) Historical towns like Barcelos, Ponte de Lima and Valença do Minho at the Portuguese side and Tui and Redondela ( but if you want the best albergue there, walk on for 3 kms to Cessantes where is o refúxio de la Jérezana., far better than the noisy and smelly big municipal albergue in Redondela.
cons. With rainy weather it is not nice to climb the highest point of the entire caminho Português , the Alto da Portela Grande between Ponte de Lima and Rubiães.can be very slippery walking on big rocks.
I walked all routes , Lisbon to Santiago ( from Porto the first 2 days along the Ocean and then turned to the Central in Vila do Conde and a second time in Caminha
one time walked the central from Porto via Maia and Vairão and one time walked the complete coastal by A Guarda and Vigo. The last time I started in Valença.
if I should do it again. Recently one of my knees has been operated so I am recovering now but if… I should walk along the coast to Vila do Conde and switched over to the central onto
Casa da Fernanda. Then took the train nearby Fernanda to Viana do Castelo and walked from there the Coastal to Vigo and connect in Redondela to the Central route to Santiago.