Whether they are any good or not is a bit irrelevant to you. Those batteries are a bit on the weak side to power your Emaxx. Ideally you would want batteries that can support around 150A. The ones in your link can only sustain 100A (maybe less) which might not be enough for a 1/8th brushless system. Think in the region of 5000mAh + 30C and up from there.