snavenayr, I walked the Frances in February of this year. There are advantages and disadvantages, but I'd do it again.
Sometimes people can pass Roncesvalles easily in winter, while it can be hasardous in May (as it was in '10.) I found the alternate route to Roncesvalles was a charming walk in its own right.
Treating all my clothes as potential layers helped with cold. Why carry when you can wear? An
Altus jacket over one jumper and several thermals was sufficient for both wind and wet. Surprisingly, gloves can be a problem, since most good ones are designed for snow not rain. I might opt for greasy wool mitts next time: easy to get on and perform when damp.
I only had one small accommodation problem this February on the meseta. The absence of pilgrim company was a chance to get more with the locals. (The people of the Bierzo region were particularly nice.)
I suppose the advantage of the Frances is that it never really stops, and help is seldom far even in the harshest weather. Also, it's pretty open walking, with the track well defined. Much as I love the Le Puy route, the Aubrac could present problems early in the year. It was fairly brutal even in Spring.
Hope this helps a little.
Rob