I was a little uneasy when I bought this product as I've had laptop/notebook cases like this before and they haven't protected my machine at all.
This however seems to do just fine, it's got a rough material outside but a smooth material inside, don't get me wrong, the inside isn't soft. It's just smooth.
I've been using this case to carry my HP Chromebook 11 as this was in the recommended products for the Chromebook when I bought it. The 11" Chromebook fits fine and has a little room for A4 paper which is great as I carry printed documents with me as this Chromebook is for college work.
I can't say I've done a drop test and I probably won't do a drop test, but I can say this case has saved my Chromebooks glossy shell from getting scratches and marks and I've got marks on the case.
The velcro that holds the case/sleeve closed does a fine job, it's easy to pull open but hasn't opened by itself or not stuck closed properly.
Overall, I think it's a great case/sleeve for the price, I'm not sure how well it will do with drops but for keeping your laptops free from scratches it works great, I will be continuing to use this product.