Not sure about the "externship." Same as away rotation? We do get some medical students rotating through from other medical schools. The only thing I can say is that the hours are good, the people are friendly, and the atmosphere is pretty lade back. You will have a good time here if you come.
What I can tell you more about is the residency. I am at the end of my CA2 year. Honestly, I love it here. My fellow residents are awesome, the attendings are awesome, most of the surgeons are awesome

. The longer I spend here the happier I am about my choice the train here. We get great variety of cases and a lot of pathology. I cannot remember how long it has been since I have done an ASA1 case (outpatient surgicenter rotation?). Usually those cases, if they come to the main hospital, are done by the CRNAs. Most patients have something that keeps you thinking during the case. You want this. It is good for your education, and makes the day go faster.
The hours for residents are pretty cush. Sure you will have some long days of even long weeks, but for the most part, no one can complain. My average weekly hours are 50-60 and this is supposed to be the most hour intensive year next to internship.
In short, you get a great education at a top program without being overworked or abused. There are some amazing docs here that have literally written the books on the specialties, and expert clinicians who are some of the most talented and capable clinicians and teachers I am sure I will ever have the privilege to work with.
Ender