I love Brooks Brothers! I'm not specifically in the demographic (every time I walk in it seems to be those in their 40s-60s), but it's a great place to pick up some well-made, well-cut business clothing - suits and shirts especially. (I think they've tried to appeal to a younger demographic with Black Fleece....but not sure how successful that foray has been.)
The styles can be a wee bit old-fashioned and "American", but they are classic. I also love the high quality fabrics - no polyester or nylon in sight - lots of wools and cottons.
The staff are professional and extremely helpful and add a nice personal touch. A suit I bought ended up not fitting right so I returned it, and the sales person sent me an apology note shortly afterwards saying sorry that it didn't work out. Wonderful customer service.
Because I want them to do well, my only recommendation for Brooks Brothers is to move to a street level location or to a mall for more foot traffic. I know they are trying to appeal to the lunchtime banker/lawyer crowd, but when I walk in it's always pretty empty. I imagine weekends it can't be any better....