Tonight I recorded at an outside venue I frequent, which has an incredible FOH (Brandon Cecil of Impact Audio--plug!) I recorded a SBD feed, a forward set of Schoeps Mk. 5 in cardioid (DIN) and a rearward-facing pair of Mk. 41s (AB at 60 cm). I figured I would use the envelope function to essentially add applause to the mix at the end of songs, and after solos. What I didn't anticipate was the extra dimension that those rearward-facing mics brought to the mix. It was as striking as the first time I made a SBD + AUD matrix. There is an entirely new sense of depth and spaciousness to the recording that is truly mind-blowing. It is extra work, with extra channels, but it was definitely worth it. So glad I tried it. The DR-680, fed 12V from a Naztech, performed flawlessly.
Addendum: Three clips down the thread with solo forward mics, SBD + forward mics, and SBD + forward + rear mics.