Thoroughly enjoyed it. At the time I was there, reserving ahead was a really good idea unless you're bringing a tent. In Somport-Candanchu I easily found a bed at Refugio Pepe Garcés. The next night I wanted to stay in Castillo de Jaca but had to stay instead in Villanua as nothing was available in CDJ. It just meant a more leisurely day of walking. In Jaca there was plenty of options. Thereafter towns are more spread out and choices fewer. Timing seems to make a big difference as I was able to stay at the Albergue in Artieda. A woman I met who was in Artieda the day ahead of me was not able to stay there. Really enjoyed my stays at El Pension de Peregrina in Sangüesa and the Casa Rural in Monreal. Many albergues are reducing their capacity due to covid. If you're not a fast walker and won't arrive early, best to book ahead.
Depending on your itenerary, there is now a newly opened Albergue in the village of Canfranc. The pictures on gronze.com look impressive.
For more info on this route I would check out gronze.com if you haven't already. This route is listed under 'Other Caminos' at the bottom of the page.
Buen camino!
@pinkwadingbird and
@Amy Mello have given you useful tips. The most important thing to note is that there is little (i.e., nothing) in the way of support between pueblos, so care must be taken to ensure that you have enough water. Accommodation has always been limited on the Aragonese, so reserving is not a bad idea. I have starred (*) places where masses were being held, but this is an ever-changing situation, and the mass-going pilgrim will need to enquire locally. The barman and little old ladies are your best source of info. Jaca* has a church of Saint James, where pilgrims can be found as many start from Jaca.
I always urge people to take the opportunity to visit San Juan de la Peña, which is among the top five travel experiences of my life. If you have the option at all in terms of time, do it! I stayed in a very nice middle-priced inn in Santa Cruz de los Seros, on the way up, and enjoyed a wonderful evening watching the sun's rays setting over the old church.
I have visited (but not stayed at) the albergues in Santa Cilia and Artieda, and they appear to be excellent. Ruesta was crowded on the day I was there, but its setting at the side of an abandoned town was incredible.
Sangüesa* had several options for accommodation-- friends stayed at a camping as the single albergue was full, although I stayed at the Yamaguchi on the SE outskirts. The path to Monreal is a great stretch but friends telll me that the Lumbier alternative route is breathtaking-- sadly I didn't have enough breath at the time but should I ever go that way again, I will. The albergue in Monreal is in an historic building and has a single large airy room-- desirous of my own bathroom, I stayed at a lovely little casa rural (Exartanea) near the plaza, as mentioned by @pinkwadingbird .
The albergue at Tiebas* was also pleasant, but as with the other accommodations I have mentioned, will require a call to see if it be open. A few km east of Puenta la Reina, make sure that you take the detour to Eunate to see the octagonal church there. AFAIK the albergue there is not open.
Northern Alternative: One year I took the route north of the Embalse, and stayed at Rincon Emilio in Berdun*, a family-owned hotel on the plaza, near the church. The route to the monastery at Leyre* is a tough 32km, mainly because one must use the narrow verge of the A-21 for much of it and the exhausting 4km uphill to the right from the NA-2420 after Náutica de Leyre. However, 26km out of Berdun one can experience the hot springs at Tiermas should the lake not have risen. The turismo officer in Javier told me that it is a secret but all pilgrims will benefit by the mud baths. If you take this variant, the next day you will be able to visit Castillo de Javier*, where Saint Francis Xavier was raised. I do not know if the Jesuit Fathers provide pilgrim accommodation, but it never hurts to ask. There is at any rate a small hotel opposite, and they were very hospitable at lunch. The Misioneras de Cristo Jesus have a house ESE by a km but I do not know if they offer pilgrim hospitality.
This is an exceptional Camino to take for the mildly adventurous and determined pilgrim. The pilgrim population is much smaller, perhaps 20-40 per stage, and is primarily European, the landscape is barren and spectacular, but the locals are warm and hospitable. There is no pack transport that I know of, and the mass-going pilgrim will only be able to attend sporadically but it is a route you will not forget.