Hi
Step 2 timing is a tricky thing. Here is the advice I received on a similar q from posters on this board.
Timing of step 2 is an issue that depends on the overall strength of the applicant. Other factors to consider.
1. Step 1 score
2. 3rd yr rotation evals/scores
3. Gas rotation scores
4. US vs IMG
5. Personality
6. Inter-personal skills
7. Publications ?
8. Connections in the department (HUGE!!!)
If you're a cool cat that did well on S1, 3rd yr rotations, did well on a gas rotation, and are a US student, then chances are pretty good you can take S2 that late and still get a strong residency. I've seen different admission comittee scoring sytems, and S2 places around 3rd place on a list of importance. Btw, these sytems were posted on this board somewhere. On the flipside, if you feel you may be an otherwise "weak" applicant, then a strong S2 can go a long way in the admission eval.
I am also in the application process, and the glaring hole in my app is my IMG status. My other fields are pretty strong, but I don't want to take any chances so I am gonna drop bombs on S2 in september. I have heard from a few people, including a university based PD and my own advisor, that I won't have any problems securing a spot. They say that although I am an IMG, which unfortunately is a red flag at many programs, my 3/4 yr grades and S1 score will open the door, and my people skills will walk me thru it during the interview. I think it may help that I am a US-born IMG with no communication barriers. Even with all of this, I wanna take S2 in order to try my luck at a few top-notch programs.
Hope this helps
Peace
Lo