To follow up with Jeff Townes' review of the Mk3, I'm rather shocked at the monitoring issue he reports (single mic tracking to one track = mono monitor output to one channel only). It's surprising given the monitoring flexibility on the Dr60, 70, 701, etc. And we haven't even started with M/S monitoring (although according to the manual, the relevant options are available).
I thing I'll stick to my D100 (and save up for a USBPre2).
(Btw, this was my first post on TS - Hi, everybody.)
There was also an update re mono recording in Jeff Towne's review:
"UPDATE! Another helpful reader asked if there was a downside to using “MONO-MIX” (set in the FILETYPE menu) when recording with only one microphone. This mode combines the left and right channels into a mono file, and routes sound from each input equally to both channels of the headphones. In theory, this is bad practice: recording an “empty” track into the mono mix file can add noise. This used to be a real problem on some older recorders. But in practice, on the DR-100mkIII, any noise created by the unused channel is so low that it’s inconsequential, so using mono-mix mode when recording with one mic is a viable workaround. Just to be safe, I’d recommend turning the input gain down on the unused channel, the new Input level switch makes that easy to do."