You don't understand buddy. You don't want to or just don’t know the difference between the real/actual STA and effective STA.
Yes the effective STA on the Amflow is pretty much spot on(to correct you it's 77°) what man would want but I am talking about the actual STA(70°) that pretty much negates a good effective STA when it gets really steep, especially on bikes with kinked seat tubes and like I said in my first post if you are tall(it can be but it's not a huge problem for average height folks). A good actual STA for an mtb/emtb is cca 73°+, everything bellow is not really what you would want. The best climbing bikes on all tests have strait seat tubes(tell me why).
Where do you ride, CA hills...not really steep there is it? I live and ride at UCI Wold Cup DH location, trust me I know what steep is. Actually this week-end The Santa Cruz Syndicate team is training and testing here, previous week it was Mondraker...
Sorry buddy but you need to go read a bit more about mtb geometry if you want a conversation with me, and next don't need to be sarcastic if someone has a different opinion or more experience

good luck