The jet black is definitely much...stickier (in a good way). In the summer, its difficult to assess the slipperiness, but when the hands are dry, the matte black (and other "matte" colors) are definitely slicker. If you use a case, it doesn't matter. I loathe cases, so I'm tempted by the jet black despite the scratches; I have the matte black now but have a jet black through IUP reserved for next week and have a feeling the grippiness will win out
If you have a store with both on display nearby, check them out in person; it's hard to know exactly what people are talking about in describing them as "grippy"