I want to be able to get a better idea of my "true" energy consumption and understand what really is the most efficient way to charge (ie. 40A max or something lower), so I picked up a very cheap meter on ebay. The meter comes with and only uses a single CT, so it assumes that the charger is balanced between each phase. So far that appears to be the case, as it is generally very accurate when compared with the display shown on the car. I'll update with some information after I've had several days/weeks to measure and calculate some efficiency results.