The idea of sun/moon augments is brilliant, and something we have been asking for for some time. Well done. As an improvement, I think the slots should be opened to more items. Some set bonuses are also missing, not just MRR cap. For example, can you bring the % to spell points that the LGS gives? You have completely forgotten it in the current sets. And one very frustrating thing about LGS is that it doesn't have augments slots.
Can you consider the idea of updating the 3 set-augment-bonuses from raid items, devs? It has always seemed very abusive to me to need 3 slots and 3 raid items to be able to obtain only one set benefit. If you want, maintain that three raid items are needed, but please make those three items form a single augment that only occupies one slot.
And now, my disappointment regarding the new equipment: the items themselves are frustrating. Important stats that are very difficult to find are missing, such as quality ability, or spell lore (a stat totally forgotten since you designed the spinneret with Slavers loot!), or insightful/quality spell mastery, or even freedom of movement! Devs, it is very difficult to change equipment when the important stats on the items are so scattered, and in some cases forgotten.
We need more thematic items that group together important stats. We need fewer stats that do nothing, like break sheltering and resistance, or the quality saves. And we need better integration with another previous items. For example, we have some items with those important stats in other expansions, but they conflict with slots where there are now sun or moon augments. A less random loot design is needed or give us more crafting options so that we can set the stats we need. Or alternatively, allow us to update old items to the new moon/sun system, although I think this would be more difficult to code.
And instead of filler stats that are useless, bring us nice things, deific focus style, dots, clickies, increased boosts, etc, etc, which are what should define the new loot, not the same stats thrown between the items randomly.
Looking at these items, as much as I like the moon/sun system, I am left with a bad impression, because I find it difficult to replace my current sets without losing important stats. Please, please, please, we need to make it easier to integrate all the stats. We need to make it easier to replace one item with another. The sets are a barrier, of course, but so is how difficult it is to integrate the essential stats of a build into the items themselves.