I've walked both branches. After walking the VDLP and Sanabres in early 2018, I found myself with a whole week to spare in Santiago before meeting my son (I had allowed for 5 rest days along the VDLP but feeling full of energy, enthusiasm and momentum, I never took any.) Returning by public transport to Granja and staying once again at the now familiar municipal, I walked the short way to Astorga. While I loved the Sanabres for it's scenery and it's challenging terrain, there was a somewhat odd, melancholic feel about the walk to Astorga. Of course, finding yourself suddenly alone after a month or more of pilgrim company can do that, but I loved it anyway: a stretch of abandoned Victorian railway line into Benavente where the albergue is in the old station, on through strange empty towns and villages with dusty streets and little mounds of wine caves, some astounding street art in La Bañeza and a beautiful approach into Astorga that doesnt involve that godawful railway bridge. I continued walking for two more days over that lovely mountainous but busy stretch of the Frances into Ponferrada where I took the bus back to Santiago to meet my son and we would walk together to Finisterre and Muxia.
Granja de Moreruela to Astorga is four days of flat, easy walking. I wouldn't really call it unremarkable as I found it quirky and atmospheric. It was quiet and I didn't meet many pilgrims, but the local people were very welcoming and friendly. I enjoyed it and I hope you will too...