I left SJPdP on Nov 3 2013. First 3 days were drizzle and rain pretty much throughout, but little rain after that apart from 2 other days separately. I sheltered on one of them. Not a lot of mud except one day after Burgos when crossing through farmland. Generally clear skies, cold mornings and nights and lots of sunshine, even in the normally windy and wet Galicia. I think I was exceptionally lucky.
Personally I would go for a light boot. You can never count on what the weather will be, especially in these months. If it is indeed *a light boot*, it will give you the support and protection without much weight. The hiking shoe will be lighter but risks a lot of discomfort and uncomfortable if it becomes wet and cloud. On one very wet day there were a lot of large puddles to skip through and around, and a few stretches where I gave up and just walked through them as too wide to avoid - the boot definitely helped then.
But you could equally say those days were only 10% of the trip, and you could put up with a shoe and some discomfort for the benefits on the other 90%. If of course it's the same ratio this year !!
I used north face boot with vibram sole. It fitted well and so no blister problems. But everyone's foot is personal to them and you may prefer a different brand. Next time I will probably use the same but am testing a light boot from Ecco. It is still a boot, high to cover ankle, decent tread and waterproof. But lighter than the north face. So maybe you can get the benefits of a boot and get close to the lightness of a hiking shoe.
But the choice is always yours. Most people I saw at that time were using boots but there were a few with lighter alternatives and they didn't seem to be struggling too much. But I don't understand how one of them with very open shoe would have managed the few days of wet, mud (and one of light snow).
Just my experience - good luck with decision and Buen Camino !
Tim