Dorans Blade Start is still your best bet on every ADC. Its fairly arguable that it is actually better the old Dorans Blade. Now let me explain this:
Old Dorans Blade
- 80 hp
- 5 life/hit melee, 3 life/hit ranged
- 8 attack damage
New Dorans Blade
- 70 hp
- 3% lifesteal
- 7 attack damage
So how is this better?
Technically... until you are doing 100 attack damage per hit it is explicitly worse. You get less life per hit (since Lifesteal is applied on the damage done after armor mitigation) than the old Dorans Blade.
The key to the new Dorans blade is it's potential for mid and mid-late game. Since it now offers lifesteal, it scales WITH you.
There are some other points worth mentioning. Other early game lifesteal items got nerfed in the last patch too. Both Bilgewater Cutlass and Vamp Scepter only have 8% lifesteal now.
- 800 gold
- 10 attack damage
- 8% lifesteal
2 Dorans Blades:
- 950 gold
- 14 attack damage
- 140 hp
- 6% lifesteal
What does this mean?
Essentially, it opens up a lot more build paths for AD Carries.
Prior to this patch, ADCs had two options:
- Build Bloodthirster/BotRK first
- Lose lane
With the changes, ADCs can go double dorans into Infinity Edge, or any other non-lifesteal based late game item. Which increases the power of pretty much all auto attack reliant, non-ability based ad carries (Tristana, Ashe).
I guess I went on a bit of a tangent, but this is the reasons why you start Dorans Blade, because it is better.