I've walked all the stages from Deltebre to Logroño on the Camino del Ebro, although not in one go - and "backwards" from Logroño to Tudela.
I liked it very much, although my favourite landscape was around Gandesa, several days before Zaragoza. From Zaragoza to Logroño it is mostly very flat, tediously flat. But there are many compensations; for example, shortly after Gallur it was so clear that I caught a glimpse of the Pyrenees, over 100km to the east. The public park, El Bocal, near Tudela, and created when they built the irrigation canal del Ebro, is a delight. You pass the "island" of Barrataria, where Sancho Panza was governor. There are examples of local lad Goya's juvenelia in Alagón and near the Pilar in Zaragoza. A kettle of vultures (and a Roman aqueduct) at Alcanadre.
Along the way you'll be able to enjoy several tasty DOC wines - from Catalonia's punchy Priorat, past Campo de Borja, best known for its reds, but where last year I had a really delicious oaky macabeo - you'll probably get buffetted by the local cierzo wind (gentle breezes tend not to get given names) - through Navarra and ending up with some always reliable Rioja.
There have long been plans to turn the monastery at Veruela, just off the camino, into a parador. If they eventually finish it (originally intended to open for Zaragoza's Expo 2008) it will provide an excellent excuse to get back to the Ebro - it's partly 12th century, possibly the oldest and once the largest Cistercian abbey in Spain. Also where Bécquer wrote his "Cartas desde mi celda" in "mi escondido valle de Veruela".
@SabsP is right about it being lonely - I saw no other pilgrims between the Mediterranean and Logroño.
The pic is of the Ebro near Alcalá de Ebro ("Barrataria"), not far from where Don Quixote first saw the river - "la amenidad de sus riberas, la claridad de sus aguas, el sosiego de su curso y la abundancia de sus líquidos cristales".
