V3 Cadence vs. Cadense/Speed sensor... what is reported?

I note that the V3 now measures cadence... does the V3 cadence overrule data from a cadence/speed censor?

I ask because it seems that both watts and cadence, as seen on my 1030, report simultaneously... e.g., when coasting they both report 0... upon spinning again, they fire up at the same time. Finally, it also appears that my speed data is a bit jumpy, much like my cadence data, which leads me to believe that the V3 data on cadence and the 1030 GPS speed data were the reported data on my screen.

On by the way... kudos to the V3 engineers... very nicely done...