Some items possibly helpful on the Salvador / Primivo are:
1) Hotel Real Colegiata San Isidoro in Leon is at the upper end of most budgets but a beautiful hotel with an attached church with a really nice Pilgrims mass.
Buffet breakfast is among the best I've had.
2) Plaza San Martin in Leon is a really busy, exciting place to eat. I have eaten at Tabierna Los Cazzuros twice and it is quite nice even in the off season (early May)
3) La Robla is a bit industrial so I kept going. I liked La Pola de Gordon. I stayed at Hotel Valle de Gordon which was clean but a bit utilitarian. Meson de Miguel is a nice place to eat supper. They made me a great Ensalata Mixta.
4) The walk from La Pola De Gordon to Pajares is long and absolutely beautiful. You cross two mountain passes / big hills. I walked in mid May and the ground and path was dry and easy to manage. Some snow is visible on the higher mountains. Splitting it up into two days is a good idea.
The only option along the way is at the CR in Poladura. You will need to book this in advance and ask for dinner as there are essentially no services between La pola de Gordon and Pajares. For those worried about their fitness, I wouldn't worry too much. Just take it slow. Really no harder and likely easier than the Napoleonic route from SJPDP to Roncesvalles. Call the day before and book your dinner in Pajares. I got lucky and they squeezed me in with 3 other pilgrims for supper at the local restaurant. The albergue in Pajares is a typical converted old school house. There are no clean sheets on the foam mattresses so you may wish to put a small bed sheet on them. I am a bit particular.
5) I got briefly lost twice between Pajares and Campomanes. Watch the trail closely as there are some co-existing hiking trails with slightly different
trail markers which utilize the Salvador (and Primitivo) at various points. In the cases I got a bit lost I really didn't lose much ground (or energy). I did
use the
Wise Pilgrim app with my cell phone GPS and found my way back somewhat quickly.
6) La Pola de Lena is not much when you enter but the Plaza de Mercado had lots of nice restaurants and I really liked this little town (central core).
7) Mieres is a busy city / town and good option if you want a short final day into Oviedo. I'd probably stay in a hotel here also as the reviews of the Albergue weren't great.
8) Oviedo is absolutely beautiful. Pick up your "Salvadorana / Compostella" at the Albergue (which has a bit of difficult buzzer system to get into). The Salvadorana gets you into the Oviedo Cathedral for free so buy a little tube to protect it on the Primitivo and bring it with you to the Cathedral. I stayed in a small hotel downtown and really liked it. Oviedo is a gem. I could easily have taken a rest day here.
Regarding the Primitivo, there is lots to say.
Overall it is very beautiful and there are many opportunities to meet pilgrims which is nice after the solitude of the Salvador. I stayed in a mix of hotels and albergues. Regarding the fitness level required, it is certainly doable for people of average fitness, it just may take a bit longer. The only tough isolated stretch is the "Hospitales" option. I enjoy challenges (took the Dragonte Route to O'Cebriero), however there was not much to be gained by the Hospitales route for me as I would have had a very short previous day (10km) day in order to do it. Pola de Allande has some nice bars and is quaint. The walk back up the mountain the next day does bring you into the mist a little bit but only briefly. I wore shorts, wind breaker and merino wool sweater in mid to late May and that was the only day I was a cold. For 30 mins I wished I had gloves. That being said I am from Canada.
Definitely spend a night in Lugo and have dinner in the old city. The walk from Lugo to Melide doesn't have many albergue options. Melide to SDC is very busy and a bit of a shock after the previous 2 weeks of walking. I really like O Pedrouzo and have eaten twice at Taste the Way which is a bit "hipster" according to my daughter but definitely a nice treat. The next day into SDC is only 4-5 hours. Leave by 0800 and arrive for lunch.
Have fun
Jamie