First off, IE builds out of two **1300 gold items** that have no components and costs a massive **3700 gold** (1100 to combine into). **This feels shitty to build.** You can't even build it first because of the doubled crit, leaving ADCs to change builds from BF -> Zeal -> IE _Zeal Upgraded to BF -> Zeal -> Zeal Upgraded -> IE, which is a lot worse as flat AD is much better early. It should be the old build path with its 3400 cost and should reduce the true damage convert to 10-15% (probably 12%).
But there are more issues. People have done the math and figured out that with 20% true damage convert, ADCs deal more damage to targets above 125 armor, less damage to those under 125. But marksmen items have gotten a huge cost increase, which brings me to my next point.
They're just making marksmen's damage take longer to come online. That's not fun for anyone. It sucks for the marksmen player because their character isn't really playable until their damage comes online. It sucks for everyone else because once their damage does come online, nothing really changed and we're back to the same low interactivity.
There's no item that gives Crit and CDR. What are Sivir, and more specifically Xayah supposed to go 1st item? I can see Sivir taking up the new Essence Reaver and Xayah just reverting back to her BoRK -> Cleaver build she did on release. The new Essence Reaver just kinda sucks in design because it only works on people who can use their ults offensively, like Sivir/Ashe. It's much harder to use on Xayah. Jhin can't even use the item. I don't know how to fix this version of the item.
Stormrazor should be ranged only. It looks like an item for assassins, not marksmen. I personally don't think assassins need another Duskblade.
The Last Whisper changes are my big part and I think Riot is overtunning the numbers drastically. Assassins were already compensated for losing Last Whisper before by gaining Duskblade and other assassin itemization. Giving them the same Last Whisper is just going to break everything. It should be 20% total armor pen on both Mortal and LDR, and give LDR some effect.
Changing BoRK with cost reduction is just going to lead us to the same exact issue we had last time BoRK's cost was this low. People praised the PBE change that made the onhit damage 6.5% for ranged. That change should go on and the lifesteal should also be reverted back to 15%.
Considering Last Whisper is being reverted, Black Cleaver should be reverted to 30% armor pen. Bruisers who use Cleaver suck right now; even Fiora is building Trinity instead. Give it the clause Wit's End has for ranged if you're worried about Lucian/MF.
Given my suggestion to IE, Zeal items could stand to be 2700 (Live: 2600, PBE: 2800) just because it would otherwise feel pretty shitty to build Crit and a BoRK meta would be forced.
Overall the changes to Crit items make marksmen unfun to play and unfun to play against once they reach their spike. The spike should be smoothened out to make the experience greater for everyone. I don't want ADCs to be stupidly powerful, but I also would like ADCs to be fun to play at least.
EDIT: Also none of the changes are attempting to fix Rageblade ADCs which are a bit overtunned, especially Varus.