DISCLOSURE:
I'm going to PENN next year so there's my bias.
In my experiences rotating through 3 different academic departments (Penn included) and 17 interviews is that the level of academia in Anesthesia is nowhere near another large field such as Internal Medicine or Cardiology.
There just aren't as many people doing research. Whether it is due to the nature of the field or size of departments, who knows.
When is the last time you've heard of prospective, randomized, controlled, double blind, multicenter trials involving 10000+ people on long term effects of anesthesia? Talk to any cardiologist and they'll start spewing numbers from VALIANT or ISIS-2 (multinational studies), the likes of which I cannot see in our field.
With that said, you can compare the money that is being spent on basic science + clinical outcomes research in the major centers across the nation (PENN, UCSF, MGH, Hopkins, Duke...and many others) you'll see, they are similar. I would tend to agree with the previous poster about secondary concerns (living situation, opportunities, package).
For me, Penn had the facilities, solid medical program, stronger undergraduate campus, more favorable city (living like a king as a resident), and the new chair (personality aside) - focusing on outcomes research (actually recruited from Hopkins), as well as a $20 round trip Chinatown bus that can get you to NYC to participate in world cultrue (altho Philla can hold its own).
Those were some of my personal tastes. I don't think there is enough difference in "academia" or job prospects between the two places. Plus I just don't get what one does around Baltimore.
With regards to work hours, I understand that both programs will push 65-75 hors/wk, but the way I see it - that is still much below most other fields (Medicine, Surgery, Pediatrics).
Good luck choosing. PM me with any more questions.