By a lot. The extra health on the egg is a downside.
The plus 1 heath is both upside and a downside it all depend on the board state. if for example you play void terror its better or if you buff its attack by 1 with goblin lackey against for example paladin it can value trade into more 1/1's that is if you want to play for the board control.
Yeah, but Nerubian egg was amazing and well above the power curve, so this not stacking up to it doesn't make it a bad card. In particular I think that this fits well into a warlock deck with Plague of Flames and Grim Rally, where it can produce value as a sacrifice.