Just got my DR-680 in the mail. I'm very excited but also a little uneasy about all of the external battery concerns. I really hope that this won't be a regrettable purchase. Luckily the first place I'll be trying this out at has reliable AC power available in the taping sweet spot, so I'll just use that, but I'm not gonna lie, I'm going to be really uneasy the first time I roll while powered by an external battery. I use a Battery Geeks battery for my DR-100 which has been nothing but fantastic, so I'm hoping for the same with this unit! Fingers crossed.
Browsing the unit now, I really like the look, feel, and features of it. Adjusting the input levels on-screen is kind of odd, but I think I could get used to it. Functionality is similar to the DR-100, so I'm already a bit used to the menu and interface. Very nice.