Opinions vary, but I have read several (about the last iteration, e.g. the T430) that are more favorably inclined to the Lenovo version of these "chiclet" keybo

Opinions vary, but I have read several (about the last iteration, e.g. the T430) that are more favorably inclined to the Lenovo version of these "chiclet" keyboards. That their action is better and that the hard topped, slightly curved keys are more comfortable. Still, though, as far as I know one of those rubber mat "contraptions", under the surface. And with the "island" style key placements (surrounded/separated by a distinct surface, instead of the keys being immediately adjacent to each other).