While I understand that you'd rather use a 1080p version for this project, you must realize that the number of pixels isn't always everything - for example, the aforementioned Ady's 1080p color corrected version has less detail than the 720p DeEd, because of compression, so if you zoomed in and cropped that, you'd still get worse results than when using the DeEd.

Also, I never said there was no loss of detail (because there is) only that it is minimal - definitely much less than there should be between a proper 1080p transfer and a 720p downscale.