Is the new Bloodthirster Viable?
Solution 1:
The new Patch changed ADCs Completely. Before this patch Bloodthirster was basically the only thing to buy on an ADC with very few exceptions (Vayne, sometimes Twitch). Now you have 3 Main Options to rush. Bloodthirster is actually none of them.
Why is Bloodthirster a bad Choice?
BT is just more of a defensive Item right now. It's a lot more expensive and it has lost its stacking power. The reason BT was so strong is because if you had The item and your lane opponent just had the components, you would still deal a lot more damage just by stacking it up. Also if you forced your enemy out of lane before he could buy a BF Sword you were in a huge advantage if you got one yourself. I guess Riot wanted to rebalance this by giving you more opportunities for building a core. You shouldn't rush BT under any circumstances I could imagine right now. Maybe you shouldn't even buy it at all.
Dignitas did a gread job at calculating how the new Bloodthirster competes against the BotrK.
Now for the rest I think you can imagine that Infinity Edge is a lot better than BT (300g more and +25% Crit, +50% Crit Damage). Basically on "Burst ADCs" like Lucian, Graves or Corki you should be rushing an Infinity Edge. Of course we shouldn't forget about the new Item (Essence Reaver) . While this Item may seem a little odd on ADCs at first it's a really strong thing to rush on a few ones. Especially Lucian, Urgot (Yes I'll put him here although noone likes him) and Ezreal wil profit a lot from the Mana and CDR. Also it's easy to build since you it's key components aren't expensive.
On pure autoattackers (Ashe, KogMaw, Twitch) BotrK will be the best choice to rush right now. It got buffed a lot for ranged champions while it was slightly nerfed for Meeles (+3% On-Hit dmg, -5% Active dmg). When playing some kind of Hybrid ADC (Varus, Jinx, MF) the Item should be Situational If you want to Push and Duel early you should probably go for a Blade while IE would be better in Teamfights.
So basically:
TL;DR
- Don't buy BT
- Essence Reaver if behind or spamming on caster ADCs
- Infinity Edge on Burst/Caster ADCs if ahead or balanced
- Blade of the Ruined King on pure Autoattackers