With the change coming, this might not be useful information but I thought I'd post an update for others who find this thread while looking for similar answers.
Did about half of Uworld MCQ's, half the Uworld cases, and read through the explanation for the cases I didn't get around to doing. Solid pass, score higher than Step 1, lower than Step 2 which seems to be the pattern.
If you've done reasonably well on previous Steps, you won't need to study much though I think the Uworld MCQ's are nice for giving you some confidence going in. Recommend doing the practice cases for sure, an EM resident will have the thought process down easily because it's what we do every day but the format takes some getting used to...
Unsurprisingly, my worst subject was the preventative OB/GYN stuff.