Wow. This one has me a more than little baffled. Not to be a total smartass, but have you even read the Classic and Low-Carb Grow! labels? They do contain different protein blends (Low-Carb Grow! having micellar casein) but beyond that... well... Low-Carb Grow! is low in carbs (shocking I know).
I'm kind of wondering if you've read the Velocity Diet articles by Shugart all that carefully because:
1) It's a low carb diet (and Classic Grow! is higher in carbs than Low-Carb); and
2) Chris explains why he thinks Low-Carb Grow! is such a great fit for the diet.
Seriously, I'm wondering if you should be trying such a challenging diet if you are asking these kinds of questions. What are your stats now? What is your current diet like?