1) Forty-five seconds.
That's how long, on average, a reader spends on your essay before grading it. You get twenty-five minutes to plan it, produce it, and proof it, and then you get forty-five seconds of a reader's—actually, two readers'—attention. These two SAT essay graders, granted, are highly seasoned, experienced, and (probably) good-hearted professional educators who are looking to give you the benefit of the doubt. They forgive wretched spelling, do not insist on sparkling intellectual discourse, and best of all, they are comfortable catching your grammatical knuckleballs. They are trained to seize on your thesis (or lack of a thesis), flick their eyes over your topic sentences (or lack of topic sentences), evaluate with dizzying speed the specificity, relevance, and insight of your examples (or the lack of...etc), pick up on any language that shows a faint glint of flair, and then use this intel to slap a grade on the essay. And all of this they do in less time than it takes for Michael Phelps to swim a full lap of a pool.
2) So what should you learn from this? Keep it simple.
The perfect SAT essay is one that can be rendered completely in four to five sentences: thesis, topic sentences, conclusion. Your introduction should be an unequivocal Yes or No to the prompt (and remember, if you fail to answer the prompt, you could write like Jonathan Swift and you'd still wind up with a Zero), with a compelling insight behind it.
The metrics used to evaluate your examples (you should have two, one personal, one non-personal, but this is very flexible) are specificity and relevance. “China” is not specific; “the handover of Hong Kong from Great Britain to China in 1997,” however, is. You also need to police your examples carefully to ensure that they're fully relevant to your thesis; I cannot tell you how many essays I've graded where the student provided a perfectly delightful example about a sibling's overcoming a stuttering disability, or Henry Clay's genius for compromise, and the more I read it the more it became clear that the enthusiasm for the example—that is, the test-taker's desire to describe something close to his or her heart—had taken over the essay, and it was no longer relevant to the thesis. There's no faster way to lose points than that.
3) There is no such thing as a stimulating SAT essay question.
When I took my Writing section (back when it was a separate SAT II Subject Test, I thought my question (“Ease does not challenge us,” it began) was a little, shall we say, inane. So I decided, as a personal service to the College Board, to do a little pro-bono quality control and tell them, in slightly forceful language, that I didn't consider this question to be their best effort. To my surprise, they were thoroughly ungrateful about the whole thing.
The point of this story is not to recommend that you follow my lead, but to advise you to prepare mentally for how you will deal with the dismal question you will almost certainly find when you open your test booklet. From the dull ore of this prompt you will need to forge a keen, sharp blade—and the trick to this is: do not overthink. Take advantage of the simplistic question to write a simple essay for a change. This is not like a school essay, where originality is highly valued. The word “originality” does not appear in the SAT essay grading rubric. The SAT essay tests your ability to write, not your ability to think with complexity and nuance. Nuance is your enemy because it detracts from clarity. Make a clear decision, stick to it, and write a sharp and solid essay. Use action verbs, a semicolon or two, and vary your sentence structure. Avoid reusing the same words over and over. That's all the graders are looking for. After all—forty-five seconds. Make your point.