I planned to walk the Napoleon on my first CF in 2013. I had already booked accommodations in Orrisson. Upon arriving in SJPdP, however, the Pilgrim Office informed me that the Nap was closed due to bad weather (this was mid-May).
I had decided ahead of time that, since my goal was to get to Santiago and to let Karma have its way, I took their advice and walked the Valcarlos. The route was fairly unknown to me since "everyone" walks and talks about the Nap.
The Valcarlos route was rough, no pulling punches. Most people would only walk it if the weather was already bad, so you were up against that. There was no uphill tempered with some downhill, it was uphill all the way. And, instead of splitting the walk to Roncevalles into two days as planned, I did it in one.
Although very cold, wet and muddy (the Nap would have been very cold, snowy and icy), the route was beautiful. Some of the Val goes along a major road connecting tiny villages and occasional taxis were tempting (one of my new traveling companions took one). Because of the road, there was a major rest stop about half-way which was very appreciated - clean restrooms, hot coffee, and was (drum roll, please) DRY.
I gutted it out, walked the entire day, and felt truly rewarded when I got to that little Chapel at the top.
My second CF, I was able to take the Nap (same time of year) and was finally able to stay at Orrison.
Both routes were memorable experiences for me and I wouldn't have traded either one for the world.
Buen Camino, my friend.