Travelon Anti-Theft Greenlander 21L Backpack - Secure Travel Bag with RFID Protection & Lockable Zippers - Perfect for Commuting, Business Trips & Adventure Travel

All I wanted was a safe, secure, comfortable "personal item" backpack for airline travel. I started with a backpack I already owned, but the zippers didn't work well, the water bottle pockets weren't easy to use, and it had too many busy features that made it scream "this is for a 10 mile hike, not traveling!".Then I tried a few different PacSafe backpacks. I will say they are very well made and are super safe and secure. What I didn't like about the ones I tried, including the Vibe 20 and 25L, plus the VentureSafe G3 15L and 25L, is that 1) the water bottle holders on the sides aren't deep enough for tall water bottles like a 20oz HydroFlask and 2) the bags are hard to pack and unpack because the sides aren't stiff at all. This is handy if you need to compress your bag for storage, but otherwise, it's a negative for my use-case.I used the G3 15L for a multi-week trip in Europe, so that's how I discovered the things I didn't like. When we got back, I returned it and came across the Travelon Greenlander. At that time I don't think there were many (or any?) reviews on Amazon, and only one or two on YouTube, so I took the risk and ordered it.The Greenlander was much cheaper than any of the PacSafe backpacks. I also love how minimal it looks, that it's made of mostly recycled materials, and also has a soft but more stuff shape that makes packing and unpacking much easier.The water bottle spot on the side works great, the hidden pocked on the opposite side is big enough for two sunglasses cases, the organizational pockets are well thought out, and it's really comfortable!I also like that it has similar security features as the PacSafe, but they're more subtle. The straps are reinforced with steel, the bag is slash-resistant, there is an RFID blocking pocket, and the top zippers can clip into a ring to prevent easy access.This is a slick bag, just the right size, and worked perfectly for a recent weekend air travel trip. I'd highly recommend the Greenlander.