Wow, this backpack is awesome! I bought it specifically for a trip around the UK so I didn't have to take such a large suitcase and was amazed at how much you can fit in it. I was a little worried about overpacking it to the point it wouldn't fit under the seat in front of me on the airplane, but it wasn't a problem. I think if I had packed it to the brim, it would have been a challenge on the planes that have a footrest in front of you, but on my other flights (like Southwest), there was still plenty of room. It also has the side cinchers that can help make it narrower, which is a huge help.And the pockets! So. Many. Pockets. But not too many pockets where you need to create a spreadsheet of where everything is. I easily fit a lot in this backpack (15" laptop and charger, 5 smaller travel bags, 2 changes of clothes, 3 books, stuffies for a kid, snacks, a few other devices, and a small blanket) and could have fit even more. The issue was mostly weight because I didn't want to be carrying around 30 lbs. of stuff. It's comfortable enough to wear, but spacious enough that you can start to weigh it down if you're not careful about what you're packing.Before buying, I was wary about a few things. One was the laptop compartment having enough padding, but it was plenty and my computer was protected the entire trip. The other was the backpack being too huge for me to wear. I'm 5'6" with a pretty average build (not huge, not stick thin) so I didn't want an enormous backpack that jutted out an extra foot and a half behind me or rested on my entire back and butt. I got the large and even packed with quite a bit inside it, the backpack turned out to be just the right size for me.I like the material it's made out of too and seems very high quality. It'll be my go-to travel backpack for a long time!