I disagree with this whole heartedly....of course you are not going to be as fast and efficient as the people who are IN the program. Why would they even make that comparison or have that expectation be any different? I did a peds cards away as a med student and as a resident and had great experiences both times. They aren't expecting you to show up on day one and be efficient and know where everything is. Yes, its a hassle to have to learn things, but it isn't SO bad that it renders you completely useless. If you are so far behind you literally can't get your work done and other people are having to step in and do it for you, its not bc you are new to the system - its bc you arent a good resident. It IS about showing up and being enthusiastic, and being a team player, getting along with the nurses and other house staff and having strong work ethic, a passion for the subject, and showing off whatever knowledge you have, etc. So what if it takes you a little bit longer to figure out how to get the echo lab, or to write a note. No one is timing those things. What it does mean is that you will just have to work a little harder. Come in earlier, stay later, whatever you have to do to get the job done. People will notice that, and instead of "this resident is not as fast and efficient" it becoems " man this resident is working his ass off and doing whatever he needs to do to get his work done and take care of his patients...oh and on top of that he is super cool."
So, while there are risks with an away, i believe they can be extremely helpful IF you are a good resident. Thats a big IF, if you are socially awkward or dont get along with people or dont have a good work ethic then best to try and trick them with your paper application. I had a lot of support from the program and received a letter as well. Its also a great opportunity for you to see how a program with a fellowship works, especially if you come from a smaller program. Where i trained, doing aways seemed pretty common and everyone seemed to have a positive experience. I agree that the paperwork to get their is a huge pain in the ass, but its 100% worth it.