@Emily D, there is a fine balance between the cost of producing a high powered cargo bike with a good battery, quality components and adequate range for a reasonable price for the buyer and creating your ultimate cargo ebike. You might want to consider doing a conversion of another bike with a mid drive. For the money, the Juiced bike is a good deal. And Torra Harris, the owner is very responsive to his ebike owners. Anything with Bosch or Yamaha motors is definitely in a different price bracket. You have to think about what terrain is like where you're going to ride and what your personal needs are for a cargo bike and determine how much you want to spend. Most cargo bikes are ridden on a paved road and are designed to carry a substantial load. You can do upgrades on your own and add suspension forks or a suspension seatpost for greater comfort. I'd also recommend doing a test ride before purchasing any ebike to be certain that the model you're considering buying is really the best for you.
Perhaps you have not spent a lot of time riding electric bikes with geared motors; they all have some sound but produce more torque or climbing power than a typical gearless or direct drive hub motor. That's normal for all brands, including Bosch (it's not silent). Hub motors and mid drive motors are two different beasts and each has its sweet spot in performance, price and serviceability, so one is not better than the other. Take the time to learn a little bit about each; Court did a nice
overview of the main types of electric motors and another focused on
mid drive motors that may give you some perspective.