A few days ago I traversed Vignemale (3298m) from the Spanish valley of Bujaruelo to Baysellance Refuge in France and circled back in a day, staying both nights in Refugio Labaza. It was certainly lengthy with almost 2500m of vertical gain and more in descent. Two glaciers were crossed and a gully of French Grade III rock was ascended. The route was generally non problematic and surprisingly well defined once on the ridge tops surrounding the normal route. From Spain we ascended via the Corredor de Moscova, a weakness in the mountain 1500m directly above where we slept. This is definitely the way to do Vignemale. This area of the Pyrenees is well known and attracts crowds in summer but this route doesn't. It is poorly defined and marked by sparse cairns. I have written an article about my experience on my blog;
http://adventuresofatasmanianabroad.blogspot.com.es/