Several factors informed/muddled my decision.
They are both great programs, and I believe most people would argue they're both in the top ten internationally. Chicago was actually #1 in Business Week's latest rankings, and it's consistently top five or ten in all others. LBS is similarly ranked and certainly the best program in the UK.
They both offered me the exact same financial aid package, although LBS said I could have all the money right away, which would have been nice. The GSB's package is split evenly over the two years.
How they differ:
Chicago allows you to select all (but one) of your classes, which is rather revolutionary in the world of business education. Most programs, including LBS, have a required packet of classes all first years have to take, usually in a cohort with the same students. The GSB only has one required class, five or six required categories of class (e.g. you pick one of four financial accounting classes), then a bunch of electives from which you build your concentration(s). LBS allows you to pick your own classes the second year, for the most part.
When visiting the schools, I got a rather different vibe from each program. Chicago seemed to be more about independence and customization with staff support to make sure you don't wander off and get a JD on accident. LBS was rather more nanny-like in its approach, which was sort of annoying. I almost expected them to tell me about curfew and required meals.
The students at LBS seemed more well-rounded and sort of unique, but that might just have been because I spent some time outside of class with them getting drunk off surprisingly strong Belgian beer...I was done after four or five pints. The GSB's rep over the years has sometimes included social awkwardness and extreme nerdiness, but any program with a Thursday Night Drinking Club (TNDC), weekly free-booze events called Liquidity Preference Functions (LPF), and a gambling club (creatively named the Risk and Gaming Club) can't be too bad, people-wise.
Each school's living experiences differed significantly, and living in London would have certainly been a more unique "experience" than Chicago. Chicago is a great town as well, though, as I understand. Many students from both programs chose to stick around after they graduate.
Chicago's brand is more powerful in the US and Asia, while London is well-recognized in Europe. However, I feel that an MBA from Chicago would transfer better to the EU than one from LBS to the US.
Finally, Chicago's Polsky Center, which runs all its entrepreneurial activities, hosts several competitions each year and really seems to put a lot of effort into helping its students either get their businesses off the ground or invest in someone else's.
In the end, I think LBS might have been a more "fun" choice, but the GSB will better prepare me to become a ninja assassin businessman. And if all fails, I can find my own fun in Chicago.
2/1/2007: Edit: I just received the "why didn't you come here" survey from London. It was quite lengthy, but I have included some of my selected answers below (my choices in bold):
1.4 Please indicate how you think we compare with your chosen school | ||||||||||||||||||||||||||||
Brand/Reputation: Worse | | |||||||||||||||||||||||||||
Cost of programme: Similar | | |||||||||||||||||||||||||||
Cost of living: Worse | | |||||||||||||||||||||||||||
Availability of student housing: Similar | | |||||||||||||||||||||||||||
Scholarships: Similar | | |||||||||||||||||||||||||||
Length of programme: Similar | | |||||||||||||||||||||||||||
Class size: Similar | | |||||||||||||||||||||||||||
Curriculum content/electives: Worse | | |||||||||||||||||||||||||||
Language requirement (In addition to English): Better | | |||||||||||||||||||||||||||
Quality of faculty: Worse | | |||||||||||||||||||||||||||
Career placement: Worse | | |||||||||||||||||||||||||||
Admissions service: Much Worse Facilities - IT/Library: Worse | |