I can honestly say here I have never seen a battery pack tear down and comparison anywhere. While I have disassembled battery packs to fix them, I never really paid much attention to the cells themself other than to test them, good - keep, bad - toss.
I think that's a great question but I really wouldn't know where to start to find that information. The biggest issue here is that there is no standard for laptop batteries, different sizes, shapes and outputs along with the different power needs of different laptop models, would make comparison difficult and since the battery itself does not have any effect on the performance of the laptop (as long as it works) there doesn't seem to be any real incentive to make comparisons.
Panasonic does make their own cells (and battery packs) which gives them greater control over quality than a company using an outside vendor but whether they use that ability, I can't say.