Its been a while since I've been on here...
Whats really awesome about the Graduate Business School is that any undergrad can take whatever classes they want there. Some of them you have to petition to get in but aside from the very few sections marked "MBA only" (probably to keep out those pesky young-uns that annoy business executives but i think its because ironically sometimes the MBAs are scared of undergrads driving up the grading curve), we have equal access to knowledge and resources at booth. In fact, the firm I'll be working at probably bothers recruiting for undergrads here because logistically its easy to knock out two birds with one stone (granted this is changing as we climb the rankings and catch the eyes of more ibanking/consulting type firms).
Anyways I'm a 4th year whos majoring in Economics/PublicPolicy + an area studies minor and the school has definitely changed drastically (for the better imo). While I can't comment on whether the average IQ of Uchicago students has gone up or down, I can say with certainty that the underclassmen are much more serious about studying than alot of people in my year were. The class of 2015 also as a whole feels alot more social and if you just picked one off the street you probably can't distinguish them from another kid at say Columbia, UPenn, or Harvard (with luck in the 4 years their here we'll mold them into true Uchicago fashion huehuehue).
One statistic that's worrying some administrators is a yearly upshoot in emergency room visits during the first few weeks of school for alcohol poisoning. These kids definitely don't have enough homework in orientation week to drown their sorrows in alcohol so I can only imagine they're having alot more fun
As for the pre-program "Chicago Careers in Business", its somewhat of a paradox. Everyone who has gone through the program basically thinks it was marginal at best and useless at worst. However, even upon inception it was insanely competitive to get into. Right now I believe they accept somehwere between 50-100 kids each year, which is like already a third of all the kids interested in business. Like all the pre-professional programs, its largely fluff and the less you already know about business the more it'll help you (stuff like etiquette, public speaking, introducing you to discounted cash flows etc.)
If I had to name one weakness of Uchicago, it would definitely be our career office. I know they're trying their best but we're soooooo far behind say Wharton in terms of getting our image out there and branding us. I've heard rumors that HYP have quotas that they mandate firms to take at minimum X number of students or they won't let them recruit there. Uchicago to this date still has no such power. For example, McKinsey didn't even recruit from our school until this year!
Also, our career office is disproportionately finance/consulting/ computer programming focused. Granted this might be because those are the only employable entry level skills in high demand but I feel pretty awful for all my liberal arts + non mathy science (bio) majors since I don't know what their going to do other than grad school or join the dark side and do consulting...