SAIS vs. SIPA vs. Fletcher vs. SFS vs. Kennedy student culture and academics

[CatsCradle]

 Does anyone have any knowledge as to what the student and academic culture is like in these programs? For example are some programs more well known to be incredibly academically taxing and rigorous i.e U of Chicago undergrad while others are more collaborative and social? I am hoping to avoid a situation in which I am inundated with readings and effectively drowned in coursework and am miserable.  Any comments and or opinions would be greatly appreciated. For reference, I plan to pursue a geographic concentration in Latin America with a thematic concentration in International security policy or international finance or economics.