The overall quality of the materials is just fine, however the sizing is really tight. From a dust protection perspective this makes sense: not much room for air to move about. It does however mean that putting the cover on requires quite some pressure on both cover and device.
The tight fit also brings me to my main concern: the lack of cut-outs for the plugs on the back; a full fit of the cover over the machine is not possible while hooked up to other gear. The RD-8 is not a portable device, so it will for most users be hooked up in a semi-fixed location; it would've made sense to facilitate this use in the design of the dust cover. Next time I'll get a decksaver instead.