Firstly, there’s the choice between salvaging the item for materials, or extracting the legendary aspect. I can’t get both from the same item. Extracting an aspect and then ending up selling it because I found a better one feels like a waste, because I could have gotten materials instead. This choice in itself is not necessarily a problem, but it lends to stockpiling the legendary items until an informed choice can be made, which brings me to my second point.
It’s very tedious to find particular aspects from a pile of legendary items. Sorting the stash tab sorts by item type first and item power second. But the same type of item can have many different aspects, and the same aspects (most of them anyway) can be on multiple types of items. To find and compare all copies of a particular aspect I have to go through the entire stash tab and transfer the items to my inventory, which I must have emptied first.
A third issue is that I can’t easily compare a legendary aspect with the copy of that aspect I have equipped. I have to memorize the values on the item I found and manually search for that aspect in my equipment.
There’s also no indication of which slots the aspect can go when you look at the item. You can see this by going to the occultist and previewing the aspect extraction, but that’s tedious. I know third-party build planning tools help with this, but that’s not to say the in-game UI couldn’t be improved either. Even adding a symbol for the category of the aspect would be helpful.
Finally, aspects which are available in the codex of power are not marked in any way. This isn’t super important because aspects imprinted from the codex always have the lowest possible roll, but it could still occasionally be a quick filter for items I definitely want to salvage.
Adding a freeform text search to the stash and some icons giving extra information about aspects on items would go a long way towards alleviating these issues.