I own two cargo bikes: a Bullitt (John Player Spezial) and Yuba (Mundo V.3). I find that each bike has its strengths, and I use each for specific situations. I am glad that there are many cargo bike platforms because each rider (or company) is different and has unique needs.
I like cargo bikes.
I have several sketches of modifications for my Bullitt; things I want to make so it can better serve my niche needs. I hope to share these sketches in the coming weeks. One of these sketches is a bag for the pallet of my Bullitt rather than a box. I rarely use a box, but sometimes I end up getting more groceries than planned and an expandable bag, because it is light and can be folded down on the pallet, out of the way, would be ideal.
I have a cardboard pattern for the bag, but need to clean out my sewing space before taking on another project. Until then, the Go-Getter bags from my Yuba works well.