Since your Step 1 score is below the average for matched applicants in Anesthesia, you HAVE to do better on Step 2 (see
http://www.nrmp.org/data/chartingoutcomes2007.pdf for the data...page 11 is where you will find scores by specialty. 220 is the average for Anesthesia). Obviously the anesthesia guys can tell you better if most programs rank using Step 2 scores, but the wisdom of taking Step 2 is:
- if your Step 1 score is phenomenal, do not take Step 2 before the match unless your program makes you. You will almost assuredly do worse.
- if your Step 1 score is average, do not take Step 2 before the match unless your program makes you. You will not likely do better and it will not help you to match.
- if your Step 1 score is below average or poor, take Step 2 and do better than you did on Step 1. This is really the only option. Step 2 is considered an "easier" exam than Step 1. If you do significantly worse than your already subpar Step 1 score, IMHO it reflects poorly on your application.
In programs I am familiar with, all prelim ranking (which would include your Step scores, LORS, grades, interview) happens the day you interview. If your score is not available during the interview, I find it highly unlikely that it will change your ranking when they receive it later. They may not even download the data from ERAS once they've done the initial download of your application.
In general, if a program has interviewed you, they have considered you "good enough" based on the objective standards...it is the subjective that further determines your ranking, IMHO.