Lehman Brothers - Offer for summer associate

Hey guys, I'm fairly new to this site. I just received an offer for a summer associate position from Lehman Brothers Asset Management and BlackRock portfolio management. I have a few questions about this. In your opinion which is the better offer? And whats the lifestyle and pay like for this position in each firm. Also does anyone know the potential growth in pay? Thanks a lot for your help, its greatly appreciated.