There are not many options in Posada de Valdeon (I tried the Hotel Cumbres based on Tripadvisor reviews but was completely unable to make contact either online or in writing) & La Begona seems to be one of the few which is open for longer than a brief season.
It is very popular with cyclists & many groups passed through during the course of our stay; either to overnight or for a large lunch.
Posada is somewhat out of the way & off the main tourist route, so is comparatively quiet, although I suspect busier in high season as it is at the head of the road down to Cain & the Cares Gorge.
The rooms at La Begona are adequate, with basic en suite in the annexe. I believe the rooms in the main building have shared facilities.
The breakfast was less than basic, almost non existent, comprising cafe, pan & er that's it. However, when we asked if we could have fruit & yoghurt they were provided, albeit the fruit was a little on the tired side.
The evening meal always began with a little performance from Amador - ' tonight ees possible...' & we would be given perhaps 3 options which didn't vary much from day to day. The portions were large & the quality variable. Wine, also of variable quality, is included.
The prices were reasonable, appropriate for the standard. I don't wish to damn with faint praise & as long as your expectations are not high it is quite satisfactory.