I had similar dilemma 2 years back, where i wanted a bag for my 15++ inch laptop and some accessories for daily use. After done some researches online, i decided to get myself a full leather briefcase. Yes, it is damn heavy, but it will last a lifetime and looks professional.
I got my briefcase from Satchel & Page, an original Kickstarter company from the USA.
The briefcase has accumulated some patina now and is getting more beautiful, totally no regrets.