I have had (still have) the Tumi Bravo backpack for years. It has a place for everything and it's easy to drop in an Eaglecreek Packing Folder with a couple of shirts in for an overnight.
But recently my corporate issue laptop has been replaced with something much much smaller (a Lenovo X240) and the Tumi is now just to big with loads of empty space.
So I have recently bought a Samsonite X Blade 2 Small which takes my laptop and ipad and a few bits and pieces and it also fits under the seat as well as the overhead.
When everything I need it in, it really is full but not overly so and in business black it still looks the part. I haven't seen this range outside of Europe though so you may need to hunt one down. They also do different sizes.
Coming from a Tumi backpack, whilst you can feel the difference in quality, you can't see it and it still feels like it will give long service.