The jet black is nowhere near as slippery.
I don't care how grippy the JB is. Even if you handle it with kid gloves, are ultra careful with it, and even if you put it in a case, it will be marked up and covered with scratches. The matte black, on the other hand, is quite scratch resistant and looks great without a case. As for slipperiness, you just need to hold it the right way and avoid drops onto concrete. Once you are not afraid of holding it caseless, it's fine.