Seems like you got a lively discussion going here about the revenue numbers!
Since a lot of people who frequent this forums are looking to get jobs in consulting, I just wanted to add that, regardless of the accuracy of the observation:
1. Revenue does not directly equal prestige! McKinsey and BCG both do a lot of great work with many interesting clients in a variety of markets, so there's no reason to dismiss one firm over the other just based on revenue.
2. Even if it did, there are many factors beyond prestige that you want to be considering when looking for a place of work. What is the office culture like, what clients do they work with, what sorts of responsibilities do you get, etc.