I read what I wrote on the BMCuser forum, and I didn't actually recommend the DR-680. Simply suggested it as an alternative option to what someone was considering using.
You see, I was a film location recordist for a very long time, in the '70s and '80s. Later on, in the '90s, I started an audio equipment rental business for film & TV, which lasted until the early XXI years.
You start to vow for products that you haven't used yet, probably because in my old times some brands seemed to warrant the quality when they released some product, and such products were more sparse... and expensive. If you ever handle a portable analog Nagra you will know what I mean.
But that did start to change in the '80s and '90s, and it's probably not what it was anymore. Tascam (formerly Teac) started releasing pro-audio products, and their DAT machines and 8-channel studio Hi-8 tape machines became a hit. I did own one of their portables, and rented it, even if it was rather fragile.
Perhaps I continue to do what I did on my business: let my recordist experience read the specs between the lines, if that's really possible, and pick what might be a good product. That's probably what I did when I suggested the DR-680.
The tide is turning on the affordable portable video market, and doing double system audio is becoming the norm. As double system audio is something I know quite a bit of, my experience may help.
Another thing is that there has been a spread in pricing too. And also several new combinations, putting together multi-channel mixers with digital recorders.
Brands like Sound Devices, Nagra and others occupy the multi-thousand niches, and others like Tascam and Roland are offering products that might become useful tools, as long as they are reliable.
Portability, size, weight and plenty of channels is key for location audio. Unfortunately these recorders demand more attention that 2-channel ones. And so require a sound person to handle them.
But that might also change with these DSLR video cameras popularity. The camera assistant is coming back, and probably the sound recordist too.
In any case, the Tascam DR-680 seems to fill above requirements.