I just helped set up and tweak a 103D on an LED. The Darbee processing has varying levels of filtering, so you get to decide how much processing you want to use (it has a button the remote). Fifth Element (which I am 95% certain was shot on film) would develop a grainy texture in some scenes as a result of the up conversion (so we turned the processing down), whereas Mad Max: Fury Road just looked better and better!
From experience, I own the BDP-93 and a Panasonic plasma. When I purchased my Oppo, I compared it to an ordinary player, on multiple TVs and the difference was night and day. It seems the Darbee upgrade DOES improve over the standard Oppo processing. But until I can compare them side by side, I can only assume I will prefer the Darbee.