[Regarding BBP Bags Industries backpack]
Granted, it appears that they were reviewing the bag from the perspective of shoving a 17" MBP in there. Those are monster laptops and its tough to find any bag to carry them in comfortably, let alone protect them from harm during transit.
But there are a couple of pictures in here that absolutely point out the biggest flaw in most backpacks....the padded internal sleeve/compartments gives a false sense of security as it protects only 1/2 to 2/3 of the laptop, leaving two remaining corners completely unpadded. Drop the bag or let it get kicked over, and you can end up with a dead laptop.
Example 1:
Look at the top middle of the bag, left side of photo. You can clearly see the edge of the laptop pushing against the ballistic nylon. That corner has almost zero protection. It feels protected and is when you carry it on your back. But let it slide off a chair or seat and it will likely fall right on that exposed edge and bust the laptop.
Example 2:
Photo showing laptop in the 'protected' sleeve compartment. Again, you can clearly see that the top 1/3 of the laptop, two corners, are totally unprotected.
Good thing they put a hard shell over that laptop because that case offers very little protection for a $2500 MBP.
The protective compartment of whatever bag you buy should completely encase the laptop, all four corners, front and back included. If you zip it up with laptop inside and can feel any hard surfaces of the encased laptop whatsoever, your laptop is poorly protected and likely not protected at all in case of bag drop or fall, even from a modest height.
This is why its so important to test-fit the laptop INSIDE the bag prior to purchase.
The only bags I've seen that adequately address this issue without needing a secondary sleeve or extra padding material are the Briggs and Riley and Tumi bags that use suspended sleeves and a padded bungee strap that holds the laptop in the sleeve. 360-degree padding is a must or you are only kidding yourself about protecting your computer.