Aways

It will help you anywhere bro. From my experience, pick 2 places you are interested in and go there. That's it. You can worry about all the other factors like whether to do one at a a place that is a reach vs. a solid shot, breaking into a region, etc., but I don't think most of it matters in the long run. Programs only care whether you did a rotation at their institution or not, not whether it was in their region, etc. So just pick 2 and do it.

I disagree with Vanilla Ice.

First, are you the type of person that will make a good impression. Be honest with yourself. If you are, but your grades/scores aren't the best, then go to a place where residents have a lot of say or where a rotation will help you a lot.

Northern and Southern California may as well be different states. If you do 2 rotations in California, you will somewhat pigeonhole yourself into going to that area, along with where your medical school is.

For example, if you really want to go to NYC, but you aren't AOA, and you're an average candidate, don't bother with HSS. However, most the other programs would love to have you. (this is where a programs reputation comes into play).

Also, if you are looking for letters of recs, make sure the program will write you a letter of rec...some programs in Cali are less receptive to writing letters - look for this in other posts....and some programs in other states say from the outset that they won't write you a letter.

Picking aways is extremely important. Pick a general region to start...then narrow it down...in no particular order...by reputation, what you want in a program, number of residents, exact location, resident input, compatability with who you are and what you want (single/married/kids/etc)...

If you want to sell yourself in the South, do a rotation in the south and send that recommendation to all the programs there. If you want to sell yourself in the midwest, do likewise.....for northeast, do likewise.
Tailor your personal statement such that it reflects the above (I did not do this, but I think it may have helped in some cases).

No matter how much you research programs as a third year, its hard to tell if you will really like an away program until you get there. As such, you need to consider how the rotation could help you outside its walls. Experience and letters are the major factors here...

My first SubI provided broad exposure and prepared me for my 2nd and 3rd SubI's... a huge benefit. But after three rotations, I found that my best letter did not come from an attending at my home program, where you are generally split between many different attendings. It came from an away where I was with one preceptor the entire rotation. I know for a fact that this letter alone sealed the deal on interview offers at three separate programs, and it wasn't from a big name guy either. In short, I think preceptor-based aways are a great opportunity to help your application as a whole. That being said, you always risk getting a preceptor you don't mesh with, and that could hurt you.

My advice, pick out a handful of places you think you'll like, and then from those pick one with broad exposure, and one with a preceptor. Doing a broad exposure SubI first will pay off at your second and third SubI's, where you will be able to answer questions and assist in multiple specialties. The precepted SubI could land you that one clutch letter. And if you are applying in multiple regions, DEFINITELY spread it out. There is no question that regionalism is in full effect, and it is not uncommon to be blackballed from an entire region (even less competitive community programs), if you don't rotate somewhere in the surrounding area.

That being said, no matter where you go its ortho...and even when its stressful or a less-than-ideal fit, it will still be infinitely more fun than counseling people about the importance of hypertension control.

I would highly suggest making a list of residency programs that you think you might be interested in for whatever reason (prestige, academics, operative experience, location...). Learn this information from your fourth years, residents, and attendings. Then, I would do a preliminary rank. I know it's way too early to really know, but you should do this. Decide what factor(s) is most important.

Don't go somewhere exotic if you want to be close to home or in a certain region. Don't go to a huge academic program if you want lots of operative experience (preface...there is a handful of programs with both but few).

The last thing you want to do is waste a month somewhere. It stinks when you finish the rotation, and leave it saying, "I guess I won't rank this place highly." These 2-3 months for away rotations are extremely valuable. If you can go work your butt off and impress the faculty and residents, you will climb up their rank list. So, choose wisely.