You should think that these keycaps would be quite grippy since they're made of rubber but these actually feel quite slippery after just several minutes of use
I bought these to replace the WASD keys on my gaming machine's keyboard, but ultimately moved them to my wife's keyboard as she seemed to benefit from them more than me. They work really well for her to not have to constantly look down at her keyboard to find WASD.
I love the feeling of the keycaps. The grippy texture makes them easy to rest your fingers on. The only bad thing is after a decent amount of use, the cutouts for the letters start to rip. Only noticed this on wasd though. Also, they can get pretty dirty.
They're perfectly functional but does take a little while to grow accustomed to their textures. I've seen comments about eventual wear but I've not encountered that issue.
They were working fine as intended until I realized these were really pointless. I left the arrow keys on, because why not, and just now one of the stems broke. They were always loose and now one broke which I don't even know how.