I'd take the 210 if you're in Miami and 208 is not scheduled to be an A380. You could get UD on either flight, but the later one allows you more of an evening in South Beach, plus arriving at lunchtime means it's a shorter day to limp through with jet lag.
Just double check what time the security lane closes at MIA though. It used to be 21:00, but that was a while ago. I'm sure others would have better information.