Just a start:

Pro: No ledge to collect dust
Pro: More storage
Con: Hard to reach top shelves
Con: Added expense

I guess, I'm wondering about the design aspect...is there a difference besides the more obvious ones?

This has been a topic on several Design Dilemma discussions and a Houzz Ideabook lately.

I would put cabinets all the way to the ceiling. Then whatever you store there stays clean. To be able to reach these cabinets, you will need a step stool.

I was in a vintage white-painted kitchen that had cabinets all the way to the high ceiling and wondered how in the world they reached up there. The trick was in the way the lower cabinets were built. There were deep drawers all along the floor level, with a pull-out "breadboard" step above the bottom drawer, in several strategic locations! I can not remember if all storage below the counter was drawers, with cabinets above the counter level.

Some folks are making the cabinets next to the ceiling have glass fronts - clear, wavy, translucent - to keep the room from looking too "heavy."

Not having soffits also gives you the opportunity to implement some design elements such as larger moldings, differing the heights of the cabinets, having above cabinet lighting, etc.

Skip the soffit and do stacked cabinets with glass fronts on the upper portion and lights inside for dust free display of decorative items and art.

Cabinets that go all the way to the ceiling help make your kitchen appear larger because you don't have that break of cabinets then soffits...it helps elongate the look. But also keep in mind that upper cabinets are hard to reach.

Yes, you will need to keep a step stool in a handy location to the kitchen.