Pure combo beats that top 4.
Personally I'd run GAT. Not because everyone's doing it, but because its the best choice considering that meta.
Really? Because, Im undefeated in tournament play versus combo with ichorid. That includes gencon, scg Indy and chi-town day 1.
What you should run, GAT or some form of baghdad bob. Bob is so flexible, it can deal with any deck and any random piece that comes around.