I did three away rotations at 3 really good institutions. It really depends on what you want out of the rotation. DO you want to learn the nuts and bolts of the therapy or have more patient care responsiabilities? I did a roation at Mayo - loved it, they have some of the most vigorous training of residents I saw with their morning conferences. There are 1.5X's as many attendings as residents so there are times when you will work directly with the attending with no middle man. They let you contour structures and sometimes see new patients on your own.
The other place I liked was Stanford, for a completely different reason. They let you do quite a bit with respect to the patient care. You saw the patient on your won and dictated every new patient and follow up. The emphasis was less on the planning and therapy, but again it was probably becuas eI had seen much of it before and was happy for the responsiability. There are other institutions that do this approach, as I understand, ie Cleveland CLinic and Beaumont.
The biggest problem I found at the institutions I did a rotation at that included the UNiversity of Chicago, was they seemed to have you rotating with a whole bunch of attendings. This ment during the month you probably worked with one attending maybe 3 times. If you are looking for a recommendation it is hard to get a really personal letter wit just 3 day interaction. I think places like MDACC do it a bit different and give you one person for like 2 weeks. BUt again it doesn't sound like you do much on your own at MDACC.
There were a couple of pieces of advices that I wish I knew before hand.
1) Sign up early for away rotations
2) If a place says no at first, don't take no for an answer unless you have talked with the departments clerkship directors and they tell you no.
3) It is completely ridiculous the regional biases. I mean it's not like we ride chuckwagons and their aren't airplanes. But some places only interview based on regional medical schools/where you did clerkships. If you ask me, this is the number one thing that ******s the field. Given this bias, I would do a couple roations (maybe 3) all in different parts of the country: EAst, Midwest, West.
4) Try to arrange to work with a known person for a week or two, if they let you. This should help get a solid letter.
5) Try to get a mix of a top 10 program + 1 or 2 smaller programs, that way if you are not a stellar candidate you still have a nice small program with somewhat of a "home field" advantage.
6) Follow up on everything. There are so many people you deal with during the process who are just administrators who lose things or misplace things. They don't mean harm but ultimately it is up to you.