Had mine for years now, had people sit on it, fall on it, spill beer on it, dance on it, you name it, it has been pretty heavily mis-treated (I knew that it would be, in advance) and it's held up perfectly well.
My cajon is semi-acoustic, and there is a volume knob which sticks out a bit, so it can be a bit fiddly to get the cajon into the case, but that's only becuase of the knob. Otherwise it fits light a glove.
The straps are adjustable and perfectly good for me (I'm tall), but I guess your mileage may vary there.