In general, the 1080p downloaded file should be superior - and have better audio - than the DVD rip. If you compare a streamed 1080p movie to a DVD, the streamed version will have artifacts and banding issues that makes it more of a trade off, due to compression. Depending on the title, the online version may have been remastered from the original prints since the DVD release (if the movie was ever released on Bluray it more than likely was), offering a far superior 'starting point' that would leave even a compressed version better than the DVD. Also, An intangible you may not be considering, is some of your DVDs may be 4:3, while a new 1080p download could be a 16:9 version. Attached is an unscientific comparison. Movie is AI Artificial Intelligence from 2001. One image is from my Plex saved ripped DVD, the other is from Paramount (paused stream, NOT downloaded - downloaded should be at a minimum no worse than streamed, and in all likelihood would be better). Two things I notice are the 16:9 ratio, and the details in the faces of the people in the back (this could be attributed to the frame paused - but I would expect the streamed pause to be worse, not better).