It's alright if you achieve complete adequacy. Sometimes things are just average. You don't need to reach the top, but you also don't want to be at the bottom. You just want to be "okay".
To hit the absolute norm of the middle-ground, you'll want to get yourself the Medium Big Green Egg. With the medium sized egg, you're not too big, but you're also not too small. You're definitely somewhere in the middle of it all.
But, in all seriousness, getting any sized Big Green Egg means you are doing something right. If you don't want something too little, but cannot handle something overly monstrous, then the medium egg is the perfect fit for you!