I'm not 100% positive but I think the clicking is "less noticeable" since the last firmware update but I can't be 100% certain on that.
As for battery life, I picked up an 11000mAh USB battery and have tested it with the device (and a DR-2D with USB > 5V cable) and can confirm that it powers it just fine. I can't say for how long but I'm sure that would give me more than enough "extra time" for a festy situation. I won't know until I get to one of those in June (depending on everything else going on -- bracing for bad news).
I think for the price point that it's a good little device. Not perfect but also not $429 like, or as heavy as, the 680. I needed P48/XLR and 1/8" and this gave me that in a pretty small, lighweight box.