I received an Eagle Creek carry on bag as a gift, which has been fantastic, which made me want to try more of their products. While I typically just use the carry on, I needed a a bag with more volume that I could check. I wasn't super picky on features since I wouldn't use it as much, but still wanted something that would last a long time. I ended up settling on the No Matter What Flatbed 4715cu in option. The #1 thing that sold me was the quality and knowing that this would stand the test of time over tons of baggage carriers. It offers a good amount of space to pack for a week of travel and the softer sides make it easy to cram in as much as you can and use the straps to keep any bloated appearance to a minimum. 4 spinner wheels would be nice, but 2 gets by just fine for me and I was price conscious. Otherwise zero complaints.
As a FYI, I also got the No Matter What Flatbed 6175 cu in, which a had thinner, non-padded exterior that gave the bag no structure. I ended up deciding on the 4175 solely for this since I felt the padded exterior on the 4175 would protect my gear better.