I ran a few more complete discharge and recharge cycles. Honestly can't tell a difference between the "A" pack and the "AA" pack. Battery Amnesia is taking around 80 minutes to discharge either of them +/- 5-10 minutes (discharged individually, not with both batteries in the PB).
Obviously that's not a large enough sample set, I guess I'll get a better feel over time and more use, but at this point, both size batteries ("A" and "AA") fit although if you're going with a pre-built pack, AA is probably better since those pre-built packs are not optimized for space and thus you have more room with the AAs. If you're going A (which is what the original size was), you probably need to build your own pack using thin tabs and optimizing for space otherwise it won't fit. But as of now I cannot tell the difference between the two packs.
Also, EMMpathy every so often reports a measured total capacity less than 1752mAH.. I had a 1480, and a 1672. Not sure what actually reads/sets that (System or EMMpathy or the EMM). Lind corrects it back to 1752mAH. But I did not notice any change in behavior of the capacity based on this value.