Should I go for the new DPUX Smart Battery, or get the previous gen DPU battery and do firmware upgrade?

I just got the new DPUX and SHP3, along with the 2 DPUX smart batteries. I'd like to pick up another 1 or 2 batteries for it. My OCD says I should just get the new DPUX batteries and pay the extra $200 per battery (based on their current holiday deal), compared to the DPU batteries. ANY reason to stay with the newer battery? Are they EXACTLY the same after the firmware upgrade?