If you have the manpower and talent to administer your own servers then clearly EY is overpriced. However the cost of acquiring said talent is significantly higher, and much riskier for smaller companies. My experience is not at as big a scale as yours, but I can see how there are increasing economies of scale of self-administration (and purchasing your own hardware, etc) as you get bigger.

However my beef is saying that you had better luck with SliceHost than EY, which to me is a non-sensical comparison. SliceHost doesn't offer any of what you're paying for at EY. However you explanation clarifies things significantly for me. EY is not very good at SliceHost's core competency, I'll tentatively agree with you here since I haven't done a lot of Slice commissioning on EY.