Expandable 21L-37L Waterproof Laptop Backpack with USB Charging Port - Lightweight 1.1KG Polyester Travel Bag Fits 15.6 Inch Laptop - Perfect for Business Trips, College & Daily Commute

Have used it for a few months.First, the good.Bag is massive. When *not* expanded, purely in the clothing compartment, I was able to pack enough clothes for about a 5 day trip, as one row, rolled & snugly fit into the built-in compression area. The 37L expansion allows for a full second row of clothes; for this reason, I could very easily do 2 weeks or more out of this bag. This is in addition to the added space in the frontmost compartment. As a result I've yet to really need the expansion because of the spaciousness of the bag unexpanded.The laptop pocket works as advertised & affords quick access to your machine. Great for TSA checks & for logical separation; no need to interrupt your clothes at all, or anything else.Now, the bad.The most concerning is that, despite using this bag sparingly for a month or two, both of the metal zippers used to get into the frontmost compartment are bent between 15 & 25 degrees. For comparison's sake, I've not seen this happen on any other bag I've owned, most of which I've used heavily for 5 years or more. This has me both surprised & concerned over the bag's durability over the longterm, given I've only used this bag a couple of times & have not come close to placing it under any excess stress.As for more general critiques; the fabric pouches in the frontmost compartment don't stretch & are not versatile at all. There are only two, so you'll have to find a less-organized solution for things like wires, power supplies, glasses, etc.Additionally, the water bottle compartment is too small & eats into the space of the frontmost compartment. For this reason, if you pull your bottle out of a packed bag, reintroducing the bottle to your bag is difficult, as things will have almost certainly shifted around inside. This & its smaller size makes the use of that water bottle pocket impractical.Water resistance is OK; the single time I was caught in the rain, some of the bags' internals were a bit damp, but not damagingly so. I'd also appreciate added pockets in the laptop section of the bag.Overall, I purchased this bag at around the $75 mark. Given the amount that you can pack into this, I was really tempted to give this 4 stars. As a bag, it's pretty good & fits a ton, gives you the flexibility to expand it further when you find yourself in need of extra space. But the durability concerns & need for refinement places it at 3 stars for me.