My vote would be for the DR-2D. The dual recording feature is it's greatest asset.
I regularly record 2 separate channels, external mic-in and SBD line in and matrix them in post. You can also matrix them on the fly but I like to do the side-by-side comparison before I matrix them.
So far I have only needed the RCA > 1/8' Line In from out of the SBD, but did just run into a XLR situation I was not prepared for so I will need to start using that as well.
Where I do not get a patch, I still record in dual mode, one recording at my desired input level as well as one at a lower level as a fail-safe.