The runbox was a perfect fit to my frame of 1.6m and 56kg, with all the strap pulled to the maximum. The bouncing was minimal and I run it for at least 4 times of around 8km. The bag is waterproof and the interior of the bag was dry after the run. My laptop seems perfectly fine. The amount of bouncing is equivalent to normal walking. I can say it is a well invested purchase since I could now continue to commute from office to home with my laptop now.
I have used the first generation Backback Lite for over a year and been very happy. The 2.0 Pro is a clear refinement and has quickly become my daily goto bag. Light and stable enough for long run commutes and spacey enough for cycle commuting when you want to bring extra lunch/clothes.
I strongly recommend to get the space bag which really makes this into the ultimate commuter backpack.