If you are a vest person (I am), a heated vest is better. Particularly if you're planning on adding it to a layered system - that is under your jacket liner instead of replacing your jacket liner.
Hell, I have removable windblock sleeves on mine (unheated) and they're even too much often enough.
I neet to upgrade soon and will probably go full jacket because I don't think the powerlet rapidfire stuff comes in vests, so I might have to leave my sleeve and pit vents open above 30 degrees, depending. If the rapidfire stuff is as comfortable to wear as the ads claim, it might be worth it.
I'd also strongly suggest going with the coax barrel connectors rather than SAE connectors to connect it to the bike, especially if you commute.
--Semantics are everything.