The answer is the Tempest does have things that the AIR doesn’t, both on the device itself (firmware) and in the “back-end smarts”. Yes, in theory we could improve AIR’s reporting of lightning using the same approach taken with Tempest. We may decide to tackle that in the future, but we are not doing that yet. As a practical result, lightning reported by Tempest will generally be better than AIR.
PS: My statement that “Tempest is more than just hardware” IS a general statement that includes more than just the Tempest hardware device. AIR & SKY are more than just hardware too and, in fact, are part of the overall Tempest System!
PPS: It is a bit of a semantic challenge to distinguish the “Tempest Hardware” separately from the “Tempest System”. We recognize that we probably need a better name for the piece of hardware that is currently referred to as “the Tempest” but we don’t have one yet. For now, the piece of hardware that you install at your house is “the Tempest” and everything else (including the piece of hardware) is the “Tempest System.”