Tumi expandable briefcase or backpack

[breitlings]

I'm looking for a bag I can take back and forth to the beach(house), client partner and private equity meetings. A day of clothes, papers, mbp, ipad air, etc. I bought the expandable briefcase today but now have been thinking maybe a backpack is better and am contemplating returning it and buying a larger backpack.

I'm 33 and in the tech world consultant and startup executive. I do wear suits but often just wear a blazer usually without a tie.