I'm intrigued and want to try them, but I worry the clicking noise would get annoying. I hold the deck a lot closer to my ears than my mouse usually is.
The switches used in the eXremeRate look to be rather close in size to the ones the deck uses for L1 & R1, so I would imagine the sound would be similar as well.
Yeah the SP is quite something special. It uses clicky buttons, but also keeps the rubber membranes which give it this softer clickiness. Not sure why Nintendo did that? Though to be fair it was also one of the first consoles to use clicky buttons, maybe they just hadn't completely figured it out yet?