I bought my R-44 new from Oade with the concert mod, so I can't really comment on it's stock pre's from personal experience. My own experience is simply comparing OCM R-44 and stock DR-680 informally. Which of them I choose to run is determined not by the internal preamps but by track count and other things like the ganged gain adjustment feature on the 680, the slightly smaller size of the R-44, simplicy of operation of the R44, etc. If it's something for which I want to use my best signal chain, I'll put the V3 in front of either one, but I don't feel that is a necessity. Often I'm running the V3 with the 680 primarily as a way to get 8 channels.