That's it in a nutshell. Timed AMRAPs are super fun, but it's a task in itself trying to stay just below what is referred to "redline" so that you can continue to perform. The hardest part is, your limit today is going to be different than your limit tomorrow, and so on. With a "chipper", you know what the prescribed work is, you know the time cap, and you're trying to complete the whole thing and come in under the cap. Trying to sustain a manageable pace is where it gets rough (depending on the chipper).
Are you registering for the games, or are you doing crossfit just to do crossfit?