The MiniR82 alas never took off, there are very few out there as far as I can tell. I have two, one is not problematic, the other will occasionally swap the analog input R/L channels (I use it now to record from a Josephson C700S with the X,Y figure 8s going digital-in and the W omni through the left Binder analog input, I also arm the right Binder channel so when I get a channel swap and the signal jumps from left to right I can mix them to get an intact W recording, not ideal but workable). I tried at least two other machines which also had the R/L swap problem, so far as I know never solved or even acknowledged by Sonosax.
I upgraded both machines to a 64Gig SSD (after dropping one machine while it was running and totalling the HD), this extends battery life to 4-5 hours running 4 channels analog-in with 2700 mAh Powerex NiMH AA cells. I now always attach a 6600 mAh lithium power pack, smaller than a pack of cigarettes and very light, running it at 8.4V (the 5V setting led to power glitches and recording failures), this extends the runtime to nearly 10 hours. I run the "swapping" machine once a week and the good one 3-4 times a week. I've looked at but not tried running the Zoom H6 and the Roland R26 as possible replacements if the R82s die. With the heavy use I give them, I have had the 1/8" mini jack fail (fixed by Lieberman Sound, who also did the SSD upgrade) and one Binder cable need rewiring (done by Vark, who also did my external power supply cables, bad ones caused glitches). Other quirks exist, but all except the R/L swapping are manageable and no longer trouble me.
I'd be happy to answer any specific questions you might have. You should know that the Binders can be wired to give either phantom 48V power or 3V, so you can run DPA 4063s in the Binders but not 4060s unless you use the DPA DAD6001 phantom adapters (rather bulky). I run 4060s or more often 4099s to a DPA MMA6000 preamp and then line-in through the 1/8" jack.
Jeff