Thanks, Marie. That post is really helpful.
Just to clarify one point. I've read that google may take as long as six months to recrawl a website. Does that mean that many of the links on our disavow list uploaded in Sept might not have actually had the (invisible) nofollow tag applied yet, and in which case may still be harming our website as far as penguin is concerned? When I read that google was processing disavow requests with the penguin update, I thought that that meant that the usual wait wouldn't apply, that everything would be recrawled with the penguin refresh, if that makes sense.
I'm trying to convince myself that our work on removing/disavowing links hasn't fully taken effect yet, and that we'll see a bounce in our rankings with the next penguin update, whenever that may be. I'd rather not take the lack of improvement we've seen this time around as a sign that we're never going to make a recovery. I certainly can't see how we can do much more work in terms of removing links. We were pretty thorough.