We are, despite widespread sentiment about "not putting God in a box," quite willing to put Him in a spreadsheet. Like the jolly stupid Hobbits of the Shire, who "liked to have books filled with things they already knew, set out fair and square with no contradictions," we line our bookshelves with pompous hardbacks about simple things like the Trinity. We have more cross-references than crosses.
I haven't yet met a systematic theology that hasn't become a sodden substitution for a life of faith and a respect for the unpredictability (or even inconsistency) of God. If we are still debating these things after 2000 years, is it possible that we're missing the point? It certainly begs the question.
Theology, etymologically, is simply the study of God. We do this when we seek His face, read His word, and discuss His attributes with others. I have to wonder if "Systematic" Theology is something of a mirage, if not an outright contradiction in terms.
If I sound biased, it may be because I am. I have not, however, completely denied the potential existence of a comprehensive creed that takes into account the vagueness and volatility of real life. God certainly endowed us (well, some of us,) with a passion for organizing things. I'm just not sure he included Himself in the list, that is, as something to be "organized." One does not "organize" a lover, or a hero; they adore them.
It is difficult to contain or quantify things that are dynamic and alive. It seems to me that this is the case with Christianity. It's going places. It's doing things. It's like a butterfly specimen: you can't pin it down without killing it.