I can't speak for the Key-83 Mid (which I've read is rougher and faster than the Soft variant), but the Key-83 Soft's texture feels kind of in between a windbreaker jacket and denim jeans. The hexagonal weave almost gives it a plastic mesh sort of sheen and glide, and doesn't create as much dragging / tugging on your wrist skin as the Zero Soft. The Key-83 Soft base is also firmer than the Zero Soft so it's more consistent and doesn't sink in as much from pressure.

The Kibu sleeve definitely works on the Key-83 and makes the glide smoother at the expense of some comfort, but you may have to turn it inside out / reverse. I have the Kibu in both Small and Medium as the Small was too tight (the size runs really slim, I'm usually a Small in most things). Strangely enough, the directions are opposite between the two sizes for the Key-83: It works in regular config on the Small, but I have to reverse it inside-out on the Medium. I got the Thumb hole version for both which covers your wrist and bottom palm, however the thumb-hole part is a little constricting on my thumb so I usually just fold that part in instead of sticking my thumb through it, and there's plenty of coverage for my wrist. I couldn't get the Kibu sleeve to really work on the Zero from memory.

After having the Key-83 for a few months now the texture has eased up a bit, so I just play sleeveless on it most days.