Ha! I got the JP-08. Couldn't resist. I never liked the Jupiter that much though (it's been almost 30 years since the last time I played one) and I don't find anything really interesting about this one either. It's nice, just not... different. Nothing jumps out at me as being unique. So far, at least.
But I did the same thing! Left it on all night, killed the first set of batteries! The ones they provide are the cheapest ever made though so they wouldn't last long anyway.
And I also would have paid more for 1/4" outputs. Same with the MS-20mini. Also either a normal USB or mini instead of micro.
I will play around with the USB connection more in the future, but it's not important for now. I just think it would be really cool if I could just pull one of these out of a drawer and plug in ONE usb cable and start recording.