T2 Rush Build IdeaWith the new update as T2 marines become much stronger, I have tried a new build of rushing T2, and usually can end game before brutalisks come out.
Similar to same old bunker bulid at the beginning, take 3 gas and wall up quickly, defend with reapers and shock troopers, econ hard if the zerg does not focus you. By the time of 12:00 - 14:00, you could have about 6 sheep and 6 cows, which is about 300/200 (min/gas), you may have more if you are under very little pressure and if you take any side gas.
Get tech lab and upgrade t2 after that. Firebats are super strong against light armor units and very energy-efficient! (see what 1 fb with walls can do

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Similar build to secure your side gas easily as well.
From now you can either start pushing if zerg is heavily building on econ, use firebats and a few T2 to push, (Firebats tank zerg units, and T2 attack zerg's buildings)
or you can also keep building econ till 500/300. Meanwhile, get the armory and upgrade marine tech.(overcharge -> con 1 -> shatter -> con 2 -> penetrate -> ...)
Around 17:00, you should start autocasting t2 and you should be able to easily take down large spines with a large number of t2.
I tried a few game against a few average zerg players, and this build seen playable. I think firebats are actually super strong and maybe need some nerf.