HBS is 100% case method, although they do supplement it with pre-term "math camp" that gives a crash course in basic analytical concepts. The case method at HBS is different than what it's like at other schools (search for an old post of mine here that explains it).
Wharton's quant reputation is a byproduct of its finance reputation, but outside of finance, it's not any more or less quantitative than other b-schools. For example, virtually all the courses in marketing, operations, and strategy are 100% case method, and even a lot of the finance and accounting classes are a mix of lecture and case method (including the 1st year core classes).
Also, there isn't any theory derivation in b-school. When they talk about "quant" it's more computationally intensive than it is about doing proofs and derivations. It's crunching spreadsheets full of accounting data more than anything else, and not doing hardcore math.
I had an extensive post about what makes a 100% case method school different than others (just do a search on this forum). The short answer is, the 100% case method is most effective for those with strong business backgrounds (i.e. business undergrads and/or mgmt consultants), whereas having a mix of lecture and case method is better for those without a formal business background.
Alex Chu
alex@mbaapply.com
www.mbaapply.com
http://mbaapply.blogspot.com