The route looks good. It may be in the write-up but the biggest issue with this route is the sheer weight of traffic in the summer months. The other is the weather in the Pyrennees. Put the two together and it can become a recipe for an unpleasant ride.
I did part of the N260 with Arsey and it was "OK". I had to peel off early, sadly, so he knows more. The following year I wanted to do it the other way around, from Cadaques west in May (I think). What stopped me was the weather on that occasion. The forecast was terrible and I ended up going to stay with family in Jaca with a view to doing at least that part again. The next day I had to route south to avoid the worst of the rain, then north to the coast. I got well and truly soaked both days and would have continued to Asturias but as I came around a corner in the pouring rain just west of Bilbao, on the A8, I almost ran into a huge pile up of cars on a bridge. The drivers were just getting out of their cars and putting on their day-glo's so had I been a minute ahead I might have been thrown of the bridge and fallen 100 ft down as the smash covered most of the bridge width and lengthwise.
Its at times like these when one wisely decides that it isn't worth "pushing on" and I came off the A8 and found a hotel in the next village.
The following year I wanted to do something similar but yet again I was thwarted by the forecast and decided against it.
I also organised a 4 day tour up there to see Canfranc station in April last year and not only did we get soaked (again) but we had to ride in snow and hail.
The issue of traffic is, for me the far bigger issue, however. I'm sure that Simon 100 will correct me where I err but July-Aug is worth avoiding. In fact one could say that about almost the whole of Spain. Sunday drivers and sightseers on mountain roads are just the bloody pits!!!
Now, I'm not trying to throw a downer on this but I think that if anyone is thinking of going to the Pyrennees, they need to have a plan B which might involve staying in the French half. At the very least one needs be ready to go without a plan in a different direction on the day. On the other hand, if the weather is good, and it isn't either spring/autumn weekend or Jul-Aug, great rides can be experienced.