Toms it gets pretty crowded in that smoky back room at the Dog an Bone when the Partners at MBB all meet up to compare applications, looking to exlude anyone who wants to join McKinsey AND Bain. Horrendous, they will think, this one doesn't understand how clearly differentiated we are, like Night and Later That Night! REJECT!The stereotypes can be fun, even a little useful, but frankly at this point you will find no meaningful differentiation; if you interview with 2 of them or even 3, you'll naturally find you like the atmosphere, people and culture at one place more than the others, but in the end it may come down to which makes an offer.You must have reasons to want to join them, and these reasons will be applicable to all of them, so tell them all the same reason assuming it's a good one. Frankly they would be very surprised if someone applied to McKinsey and NOT to BB and vice versa, unless they knew the firm very well.