The SKB case does not seem to have any wheels, which makes it cumbersome to handle particularly at this day and age. I think that 2 wheels in the B&W are already a serious flaw. However the Foldon seems to have 4...
...as does the Dahon Curl flight case (see the video in post no. 2). As a bonus, the four wheels on the Dahon Curl flight case are detachable (see the video in post no. 2).