Tbh I'm even slightly against ES being used for testing. I mean let's be realistic here; they show 0 skill of the testee because they're almost all ran the exact same way. To start, lemme break this down with a visual of our current tops and tier list: http://www.pojo.biz/board/showthread.php?t=1186615
I wanna address tier 1 and ES for this.
HAT(E): It's beyond good this format. A completely new person could start using this deck and perform well because its just minus after minus on your opponent. Between the Hands, the Dion -> Myrm MST combo, Sanctum, Moral, Ignition, etc, your opponent literally gets obliterated. It's a strong deck this format and testing against it at VDA shows me literally nothing of what the testee is capable of unless they REALLY screw up some things
Geargia: Set Armor, go. Busts out advantage ridiculously. The versatile plus this deck offers is a lot for some decks to compete with and frankly outspeeds some to the point where they can't play. I've gone up against Geargia with my infamous Battlin' Boxers and it gets to the point where I can't even play this game because even though I have Lead Yoke they have plays for the next 3 turns and then some. If they ban Armor it'll be the happiest day of my existence.
Evilswarm: Turn 1 Ophion, detach get Infestation, set 3-4, pass. Against the right deck that's literally game in a turn. Tbh I don't get much trouble only because I RARELY run anything that involves level 5 or highers (Machina Gadgets is the closest thing and it hits 2 cards in the whole deck) but I can completely understand where some people come from.
I'd also point out Bujins and Madolche but that's entirely up for debate by others.