The reason you see practically every airline pilot (and quite a few F/As) using the Purdy Neat roller bag is because they are functional, extremely durable, and over the long run, an excellent value. My first bag I purchased in 1992, and did not replace it until 2007, and I still have it, and it still works like I want a bag to work--I only replaced it when I got the captain upgrade, as a treat to myself (yeah, I wanted a Harley, but one's tastes, values, and other things change over time). You'll shell out the $ up front, but you'll be hard pressed to find anyone who owns a PN bag who wants their money back...
Chuck