I have walked both -the Napoleon and the Valcarlos route. The latter is much more easier.
Valcarlos/Luzaide (it is called both ways, depending on the language) is a traditional and friendly Basque village, with a minimarket and restaurants. You can shop also a mile before Arneguy, in the former frontier crossing, where there are big (and strangely incongruous in a rural environment) supermarkets.
The albergue has 24 places -so, as the other route will be closed from November to March, there could be a high demand. Reservation is possible, apparently (when I were there, it was a scarcely transited route).
There is no hospitalero. If the door is closed, ask for the digital code in the city hall, or in Benta Ardandegia (that's the minimarket/bar/social centre). It is a little village along the road, you can't get lost.
As I remember it, the hostals were rather expensive (it is a touristic place, in summer). On the other side, Basque gastronomy is quite remarkable (solid farm stuff, not this "nouvelle cuisine" thing!)
One of the funny thing along the Valcarlos route is that you cross the border three times. If you are used to long lines, showing passports, etc., it feels quite pleasant.[/QUOTE
Thanks Felipe, didn't know you could book ahead so will look into how busy they are getting. Gotta love border crossings in Europe! Good to hear the food will be good. Nothing like a long walk and fresh air to build an appetite!