OP these are questions I'd like to know the answer to as well! I have the Aphogee 2 step treatment, Joico K pak reconstructor and Nexxus Emergencee. Idk which is the strongest. But for some reason I like Joico the best. I couldn't stand the smell of Aphogee and the way it's so messy/drippy and made my skin sticky. Emergencee is ok but it's such a small bottle!
I did get good curl definition after using Aphogee though and I seemed to always have good hair days with Joico products (a lot of them are not CG btw), which is why I'm going back to them.
I hope someone else chimes in to give us answers!