I was in a similar situation recently, but I did a lot of digging around to find differences between these two. I haven't even started working yet (I ended up choosing the BAH offer), but here are some generalizations I came across that might prove helpful.
ACN consulting is often geared towards tech outsourcing projects for private industry. Booz does have an industry part of the firm, but the bread and butter is gov't contracting.
ACN pays a bit less, but gives a -very- good paid time off allocation. I think it was 26 or 28 days PTO as an entry level - when you added in holidays it came out to over a month of PTO as an entry level. Booz has a better salary, but almost 2 fewer weeks of PTO.
I've heard you can really work like a dog at ACN - at least on the gov't side in Booz the clients work much more the 40-hour weeks, so insane amounts of overtime are much rarer (from what I hear). I think I was expecting between 50 and 65 hours a week on avg. at ACN with 80 hours on really busy weeks, but with Booz I am only expecting 40 to 50 hour weeks on average, perhaps spiking up to 65-ish occasionaly. Fair warning: this is my impression from what I have found out, I am not sure how accurate it may be or not in reality, however.
The atmosphere at ACN seemed younger (just out of school through mid 30's) - and people dressed well, but less conservatively. Booz employees have seemed a bit older (more 30's) and people seemed to dress more business conservative.
That's pretty much what comes to the top of my head. If you have any specific questions, it might spark something else though. Also, please feel free, anyone, to add in your viewpoint if you have a different impression of something I said. Again, I haven't actually worked for either of these places yet, but I was able to find out a good bit while trying to decide on my offers...
年龄: 46
有没有亲身体会地？ 
不过，我肯定尽量争取不放弃就是勒 
