They are fundamentally different products. C2 is mainly for mood elevation, stimulation, and focus. At that, I would say it was one of my favourite products we produced. Very good percentage of bocopasides, high dose of Rhodiola, with Forslean which was underrated at the time.
cAMPH, on the other hand, is exclusively a thermogenic. It has no stimulation properties, but provides a very prominent thermogenic effect, with increased anabolism and a high anti-catabolic effect.
Which one you choose is entirely up to you, and depends on what you want in a fat-burner. If you are primarily focused on fat loss, and do not care about being 'energized' cAMPH is an amazingly effective product; if you require motivation on a cut, go with C2.