Comparison: Anyone who walked both the Via Serrana and the Camino Primitivo?

As I walked the Primitivo this year and there is the chance I might be walking the Via Serrana next year as the opening chapter for the Via de la Plata, I wonder how the two compare in terms of how hard/easy they are to walk.
I did Oviedo - Santiago in 9.5 days this May and so the question is should I plan 10 days for the Via Serrana, or 20? I know it is hardly comparable how different people perceive hardness/easiness to walk. And this is not only about climb per day but also about gravel/rock/road, the amound of water and food you need to carry and whatever.
But I would love to get a rough feeling what to expect. ... hopefully less rain than I encountered in Asturias

jungleboy said:

I have walked both but it never occurred to me to compare them, as I think that Asturias/Galicia and Andalucía are about as far removed from each other as you can get in Spain.

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I know, I am aware that the overall experience would be very different and they are hard to compare in that respect. Therefore I was asking for a comparison in how hard it subjectively felt

And thank you for your answer, as this already gives me a first idea.

I would probably plan it for end of February, so definitely far from the hot season.

jungleboy said:

The Vía Serrana is shorter and easier with less elevation change; I did it in 10 days and the Primitivo in 13. There’s some road walking (especially in the 2nd half) but not too much overall. Water wasn’t a problem for me but it was December and not hot; summer or even the shoulder season might be a different story. Carrying snacks and the occasional lunch would be enough, as there are decent-sized villages or towns each night.

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