<Ever still get cold, even with all that gear?> I know that this response was not aimed at me.... but yes. 70 MPH windchill will cut through most gear below some temperature.
Without the electric vest, with insulated riding pants, insulated riding jacket, ski mobile gloves, balaclava, all vents closed, multi-layered personal garments... my rides were 'good' into the low 40°F range, for 2 hours or less.
WITH the vest, I can reduce the clothing load, and be comfortable into the low 30°F range for 2 hours... my hands still suffer a bit anyway. Grip heaters, or electric gloves would fix that.... if I had the electric 'budget' to support the extra current.....