I think it's got the silliest marketing of any ammo. Prices are exorbitant - and published results seem to indicate that it's just another HP/JHP round - one which isn't significantly better than other HP/JHP from more mainstream companies (Federal, Corbon, Hornady, Winchester...). It does apparently expand, as per Gunblast's test on the pig.
I probably won't ever buy any - cost/benefits analysis on my part gives me the notion that I wouldn't have enough money to make dead sure the rounds were reliable in my gun - and I don't think the rounds perform that much better than mainstream SD loads. Besides that, I don't know if ES's quality control is up to par or not... their ammo is too pricey to tell, I reckon. When the marketing is really over-the-top, I get suspicious. Just me, though.