I have to agree with purplepeople, it wasn't something I had considered, but looking at the weight distribution on that bike, I strongly suspect it's going to have problems. I would not be surprised to find in the owners manual a comment to the effect that you should load the front rack first. I would also like to know what they rate the racks for loading.
I don't design cargo bikes, but I've ridden many miles on laden motorcycles, and know that it's a good idea to keep weight on a line between the headstock and rear axle. The further away you get from that line, the more...interesting, life becomes.
I've just taken delivery of a BD, and have been struck by how light the steering is, even unladen. The bike is still very stable, but wouldn't want to ride it with a heavy weight hanging off the back. And the center of gravity of that battery pack seems to be inline with the back of the rear tire. We could all be wrong, but the more I look at that layout, the worse it looks. The BD, Yute, Mundo, all have the deck area close to the top of the tire, as close as is practicable with room for a fender, they all have the bags ending at the trailing edge of the rear wheel. I hope we are wrong, it will do no good to have people going round bad mouthing cargo bikes because one manufacturer goofed.
It's good to see more brands getting in on the cargo bike market, but if this bike doesn't have good handling, it could have some negative effects on the whole scene. I think it more likely that they will do more damage to their own reputation though.
Say what you want about Surly, but they did make several iterations of the BD before releasing it to market, mostly publicly. They have good justifications for most of the design details