I think taking Step 3 before starting residency has great advantages
- You'll never get time while you are resident, you won't have time to scratch your head.
- No time wast between finishing residency and your real money making job .
- Improving your chances at the match.
- Step 3 is essentially a sophisticated Step 2 CK, it's wise taking them in one stretch before you forget all those great info in your head.