UPDATE- 10 months later: DO NOT BUY
Stopped working, no response when press flush button. Everything is hooked up properly, so the only conclusion is that the battery is messed up somehow. Utterly unacceptable.
I have to withdraw my prior endorsement.
While I previously minimized the whole problem of water waste not flushing right and the weight and expense of refills, this new problem takes it over the top. If they can't get a decent battery in the system then at least have the decency to put a back-up one for when it fails, so I don't have to drive around with unflushed waste until it's fixed. Van living is hard enough already than to have to worry about this.
I don't have high hopes that when I call them tomorrow I'll see any sort of refund. Save yourself the $600 and just wrap the bags yourself in a bucket. Lesson learned.