I've since tried the bullitt and a workcycles bakfiets, as well as the edgerunner and I own a big dummy. The workcycles rode very much like a Dutch bike, stable, heavy and for me it feels slow. It wants a very upright stance. If you like Dutch bikes you'd feel at home. My wife liked it I didn't.
The bullitt is light for a cargo bike. It's a bit squirrelly at low speeds but handles fine after you get a few minutes with it. My wife, who isn't an experienced cyclist, got the hang of it after a few minutes. The frame is more rigid (overbuilt) but that works for me, I'd probably run lower tire pressures than they had it at. I'm tall enough that the top tube was low enough to step over. Think slightly higher than a mixte rather than a diamond frame top tube. After a bit it just feels like riding a bike. According to Barb at the shop, some people get it right away, some struggle with the steering but its not dependent on cycling experience.
We really liked the bionix assist. It feels very natural, reducing the effort you put in rather than giving a push. Level 1 felt like riding an unloaded bike when the kid was in the box. They weren't sure that they could fit the bionix system on a different longjohn. We liked it enough that we're probably going to get a bionixed bullitt this spring.