This is a debate without resolution, but I think it's good for people to give opinions. In the end it's up to you. Some people love the Caminho from Lisbon, some don't
(try maggie's blog for one of those who loved it.
https://magwood.me/my-caminos/camino-portuguese/)
You can see Kimmo's live comments sprinkled through these threads, and I think it's a fair evaluation to say he and his wife are loving it, so it is definitely an individualized opinion with a lot of variation.
In part, I think the opinion has to do with the expectations, the weather you got, the people you met (or didn't meet), your body's conditions, etc. There is no denying that there is a lot of asphalt on this route, but there is also a lot of asphalt on the Camino del Norte and increasingly more and more on the Frances itself.
I was in Conimbriga at the Roman ruins a few weeks ago and I met two pilgrims. One was a Danish guy and the other was a Brazilian. The Dane was loving it, the Brazilian wasn't. They both started in Lisbon, had essentially been staying in the same places, and had experienced the same weather. One said there was a lot of asphalt, the other said it wasn't a problem. One thought the towns were interesting, the other didn't, on and on (though I will inject a judgment here, I don't know how anyone can think that the Convento do Cristo in Tomar is "not interesting.")
When I walked from Lisbon in 2008, it was hard to extract that "camino feeling," in part because there were no pilgrims and no albergues. Both of those facts have changed dramatically now. I would highly recommend the albergue in Alpriate for your first night's stay. 20 km from the Cathedral in Lisbon, it is an albergue run by the Via Lusitana (the Lisbon Amigos group). Good place to meet those who will be in your "pilgrim cohort" and to get up to date information from the hospitalero/a.
In opinions as in all else -- vive la difference! Bom caminho, Laurie