Hi everyone,
Well, I'm new to this site and this forum, but I wanted to go ahead and add my thoughts as well. I actually disagree with everyone who has posted here. Overall, I think the decision to do a sub-I at another institution completely depends on what type of student you are.
There are obviously some students who are just that. They are wonderful students with great grades, board scores, and who have an application that speaks for itself. Then, there are others that shine during their clinical years and how they work on the wards shows how valuable they can be to a program. Simply put, if you are a hard-worker with a personality that is easy to get along with (which should be most people applying for pediatrics anyway), then doing an away sub-I can only help you.
"Doing bad or not up to par as a sub I can kill your chances, so don't do it" If you are worried about "doing bad" on a Sub-I, then you should be worrying about other things than whether or not to do a Sub-I. Anyone can do well on a sub-I. It only takes some effort, hard work, and patience for 4 weeks. That's it. There really isn't any reason to do poorly on a sub-I. If you are worried about doing so, then I wouldn't recommend doing ANY away rotation at an institution that you are considering applying to.
What are the benefits? Well, I think there are several benefits of doing an away sub-I. First of all, if you are seriously considering a program, then it can give you a first-hand look of what it's all about. To me, this is the most valuable. You can read whatever you like and listen to whomever about what a program is all about, however, doing a sub-I on the wards can you give you a good appreciation of the hospital and how several residents/attendings work together. In addition to this, doing a sub-I allows you the opportunity to meet more faculty, residents, hospital personnel, and even medical students (who are invaluable sources of information). This way, lots of faculty and residents can get to know you and how hard you work and can advocate for you. Don't underestimate how much say residents have in who gets into a program and who doesn't.
Again, there is no "correct" answer to this question. I believe that it truly depends on what kind of student you are and what you plan to accomplish. If you are serious about a program and want to know as much about it as possible while also displaying who you really are, then I don't think there is a better way to do so than doing a sub-I at that institution. Just so you know, I was advised by my dean the exact same thing you have all said and heard, that is, to not do a sub-I because it's going to hurt me. I completely disagreed and I matched at my #1 choice where I DID do a sub-I. I guess it didn't hurt me too much