Here are data from today. At least in my case, the D12 has a significant advantage. It was really nice and calm. Both boosts were pretty much straight up. I actually flew two pairs of flights like this, but my most abused AltimeterThree refused to share the data from the flight on my last D16-6 so here are D12-5 vs. D16-8. Added: My stubborn A3 shared the data with my iPad. So, here are the graphs from the first pair of flights (second pair of pictures). I am gratified by the consistency between the two D12 flights and can't explain the big difference between the two D16 flights. But either way, the D12 wins by a big margin with this model. One more thing: I just weighed the actual spent casings from a pair of these flights today....and the more contemporary D12 is three grams or so heavier than the one I weighed earlier (but there’s much more residue inside the casing, which is probably why). This means that once they're completely burned out there is little difference between the D12 and D16 in an Estes adapter in mass. Now during coast as the delay grain is burning - that's beyond me.