It depends on what your reference is with the cells. I don't know much about the systems, but which did you prefer between the Kai's and the Reliks? The Reliks are the softest boot Ronix make and the Kai's are more like the Ones, kind of a medium stiff boot. If you go from Kais to the Cells, it would be similar to the jump from the Reliks to the Kais in terms of stiffness.
Personally I've always liked medium-stiff/stiff boots. I've had Transits and Company bindings and went for Franks last year and didn't like it too much. I'll probably go for Ones whenever I get riding again.