The base health increase broke the balancing between ADC

I'll use Vayne as an example: She a hypercarry who already become sa threat once she hits level 6. From the beginning of time her biggest downside was her low surviveability and constant danger of getting bursted by a Sivir, Caitlyn or Corki (Varus...)- carries which in return were worse lategame.

With the base health increase the danger of getting bursted got significantly lowered since one suddenly needs 160~200+ more health for a kill, that's nearly as much as an additional summoner Heal! This change had a signficant impact on the early game of these hypercarries. Not only have they less danger of being bursted - but their killing potential also increased! E.g. Sivir has a static 9s CD on her Q. Before the preaseon changes hitting a Q usually was enough to force a Vayne back. Now it's an invitation for her to go in and hammer Sivir down while she is defenseless. DPS comes into play much sooner than before and ADC burst lost its value.

PLEASE consider giving Sivir, Varus and Ashe (I'll count that early crit as burst) back some of their early lane dominance ! (Maye even consider improving Caitlyn's Q)