I bought one of those wheelie briefcases (normal fabric one) from the QFF shop and I love, love, love, love, LOVE it!. I used to carry a black leather cabin bag, not as structured as the QFF ones, and it looked pretty schmick, which is of course important, but the shoulder strap wrecks your clothes and the schmickness doesn't offset the overall aesthetic damage. Plus, after lugging it through several airports in a day you need serious chiropracty.
The QFF wheelie bag is no effort at all to lug around and has compartments for everything you could want. I do NOT travel light, but can fill one side full of files and the other with a change of clothes and all my usual feminine accoutrements, and still have room for foot pillows, ipod, a couple of books, the essential GHD hair straightener and so on. I don't have to make many sacrifices to fit the laptop in as well. The other thing I like is that the shoulderstrap works well as a luggage strap and the case perches neatly on top of a larger suitcase.
The one drawback, for me, is that there are separators in one side of the case to keep files apart. I think these take up unnecessary room and aren't well-configured, and that I could probably get more in the case without them. I haven't quite got up the nerve yet to test my theory by slicing them out with a stanley knife, though. Wish they were detachable.
But overall, this bag is one of the best investments I ever made.