Yeah but PoW is just kind of meh, it's just a slightly different variant of standard D&D PoW, maybe with fewer dragons, and slightly different powers, but it's in the end just the PoW, the Upper Planes on the other hand, are one of the main changes in this quest, DP has clearly spent quite a bit of time thinking about the Fall of the Upper Planes, which give exploring Nirvana a good deal more narrative weight, than visiting random PoW cities, the Fortress cities of Nirvana, the Gith warfront, the Daemon invasion points, and the Illithid cities of Nirvana, are all something unique to this quest, and that make it more interesting, than just exploring random planes.
DP has at least for me managed to make the broken Upper Planes seem interesting, it's not just about what we can get there, DP has designed some genuinely interesting places, and I want to see, if they match what information we have on them.
By that same token, interacting with the Fire Whales, is much more interesting, than talking with the Salamanders or fighting the Efreeti there, because the Fire Whales feel new and unique to our adventure, or at least how we interact with them seem unique.