I can help with this one.
In the case of the dreaded 'slave cylinder failure" you'll be chugging down the highway and when you go to pass that Harley in front of you, the tach says go, but the rear wheel doesn't hear it. Harley man pulls away and you head to the dealer for a very expensive fix.(unless you're under warranty or can fix it yourself. Mine was under warranty-2800mi.)
Basically the tach climbs almost as if you were in neutral, but the response at the rear wheel isn't there. In most cases it'll only take about 10 seconds to figure out whats going on.
I hope you never experience it.
2005 BMW K1200LT
2007 Ducati Monster S4Rs