I know I mentioned it before and I'm just repeating myself but now that I have a second character neck deep into end game, I just need to rant again: I cannot fathom how they bungled the gear progression so badly in a looter shooter. The fourth mainline one in the series, sixth in the overall franchise. It's not like they're new at this.
It is insanity that one can get best-in-slot and/or class defining legendaries on easy difficulty that are identical to what drops on the hardest difficulty rank in the game. It boggles the mind that an Epic Maliwan Synestry SMG that I got in my campaign playthrough on normal is significantly superior to the exact same SMG I had drop on Ultimate Vault Hunter rank 3.
In my past posts I thought only legendary items had the same base stat variance across the difficulty levels. In playing Harlowe through to end game and really paying attention to my drops, I realized I was wrong. A level 50 item on easy will roll within the same stat variance as an identical item on UVH5; the ONLY difference between the non-UVH difficulty and the highest UVH ranks is the odds of having gear drop with firmware. But firmware itself isn't specifically roadblocked by difficulty: All forms of firmware can drop in any difficulty, it just drops at a lower rate on Easy/Normal. If one so chose, they could just as easily farm whatever firmware they're looking for on easy/normal as they could on UVH1-5.
There really is ZERO point in playing beyond UVH1 difficulty. That is probably the best sweet spot where you can easily farm parts, firmware, legendaries, and specialization XP (you get less than UVH2-5, but things die faster which offsets the gains).
As a final aside, it seems like the rarest thing in the game isn't the Phosphene Legendary drops (needed for a challenge)... it's the damn legendary enhancement items. Two characters deep into end game, Vex with 105 hours and Harlowe with 65 and I've seen two legendary enhancement items - one Jacobs, one Vladof. Comparatively, I've gotten five of the different Phosphene drops.