If you want to know more about a hairy or highly contested subject, this is a great starting point. Content, in philosophy, is usually best got from the source. Frame though... I think you need an outside frame.
It's very hard to understand Marx, Rand, Popper, Kant or whatnot without a frame. First (eg Kant), a lot of philosophical work is overly complicated, so it's much easier approach once you have an approximate idea of where it's going. Second, a lot of modern philosophy is happens within an argument. Marx was writing in counter to Ricardo, political liberals and communists. Ayn Rand was writing a response to Trotsky, Kant and other rivals. It's hard to jump into the argument midway.
That's where SEC shines. It gets you started. It gives you an understanding of how philosophies are structured, as well as the basic teams and rivalries dynamics that you need for context. Form there, it's much easier to approach philosophy.