Probably a safe assumption. Other then the fact that earlier this month Nathan from XS said he was ordering batteries so he had brand new ones from each company to begin load testing comparisons. One video has been posted thus far. If he never ever posts another comparison video, then I would assume your right, but as he stated in the thread-More videos are to come. He may even be testing some of XS smaller batteries vs other companies group 31s. I would just give the guy a chance.
Batcap has the lowest internal resistance on the market so no other battery can compare to them. I just cant afford either but if i had to choice which one i would buy it would be Batcap.