The Kawai SC-1 Softcase looks good and looks like a good buy, but the lack of corner reinforcement and its 'left-handed' design let it down:?
1] Corners need reinforcement: although the case has wheels, they can't come into play until the case is unloaded from a vehicle. It being unwieldy (an encased 88-note keyboard always is), a corner is bound to rub against something in the process of standing it up ready to wheel, or when negotiating turns (not all load-ins are straight lines). Because there's no reinforcement on the bottom corner areas, the fabric began fraying within a couple of gigs, despite careful handling.
2] Straps/zips on the wrong side (for most people): the orientation is determined by where the wheels are, and means when using the straps (eg to load the keyboard into a van), the right hand will be using the handle to steady the case, while the left does the heavy lifting with the straps. Sadly, I'm one of the c90% of humans who is not left-handed.
Smart-looking, however, with a useful pocket for leads (although put too much in and the case won't be stable when leant up against a wall).