Well, I loved the first three books (though Bran's and Arya's stuff in ASOS got really boring at some points). I liked the majority of AFFC and the parts of ADWD that were in Westeros. IMO, Theon's chapters in ADWD are some of his best writing in the entire series.
I can live with his ramblings, as long as they are somehow connected to the story he's trying to tell at the moment. I hate it when he goes on a whole page description of what's everyone wearing and eating or when he writes whole chapters where people just go from one place to another and nothing happens in them.
So in the end everything boils down to the need to get him a much better editors, someone who will tell him that releasing an unfinished book is bad.