Honestly? I'm actually mostly happy with these changes and new additions. The AoE damage of a Summoner seems to be taking the biggest hit, but let's be honest, Summoner was already insanely powerful in that regard if you knew what you were doing. Dialing back on the AoE damage doesn't feel like a bad thing. If anything I'm more concerned about their AoE damage being entirely from ability usage. With the absence of Blizzard II and Miasma II, along with Shadow Flare being converted into an ability with a 60 second timer, Summoner is absent of any spell that inherently does AoE damage. But at least with Aethertrail stacks no longer having a timer you can be more liberal with ability usage.

Also I seem to notice mixed information being thrown around? For example, according to this video, which showcases tooltip information for actions and traits, Deathflare is shown with its 400 potency retained and no downward scaling. Akh Morn is shown to scale down to 50% potency in the same fashion as Holy or Flare, but with a starting potency of 680. So at its worst it will scale down to 340 for any targets beyond the forth. And Akh Morn can be used twice every time you summon Demi-Bahamut. But as I mentioned, there seems to be conflicting information from different sources which makes it difficult to know what is accurate.