Diablo 3 is fundamentally broken

[Yricyn]

So I've reached the point where I can do Act 1 inferno without dying. Tanking the Butcher is no longer a problem. Very few boss/champ packs give me much of an issue. Act 2 Inferno is no longer unplayable, but about 50% of boss packs are unbeatable. I had a break through in Act 1 when I began valuing resist gear over vitality. I went from 200 resist all and 50k health, to 500 resist all and 30k health. I started living through previously impossible encounters.

So my question is, if 500 resist all 6k armor works for Act 1. What do you need for Act 2?