Airline Check In --> I am traveling through europe and wanted to use a backpack rather than a rolley. So it's not for backpacking, more for urban use--walking the streets / bus & train & airplane rides etc. I wanted to check this backpack in when I fly. Anyone have any experience with checking this in? I'm wondering if the hip/backpack straps get in the way or get caught in anything. Also wondering how the material holds up of something punctures it... Would appreciate any advice. Thank you!!