Aside from a lot of dirt being cleaned up in the picture, the biggest reason for primarily working with the blu is that the HD Broadcast has a LOT of compression artifacts and doesn't stand up to close scrutiny. It also seems to be framed differently as well as having some squashing or stretching here or there compared to the blu. And while contrast boosting was done (at the expense of shadow detail and highlights in too many scenes), the DVD and HD broadcasts were very dim in places... I'm not sure why this is the case, but when I look at the HD transfers of the trailers they do not show this dimness, nor do some of the LD screencaps that I've seen.