Sorry for the late reply. I've been organising a marathon that took place yesterday.
I am someone who likes the idea of trail, but is astonishingly clumsy and uncoordinated, meaning that every step can trip me up. I have not found this to be the case on the Swiss Alpine events, although perhaps it does depend on how fast you are running.
My flat road marathon time is usually a little inside 4 hours these days as I prefer to run rather than race.
The swissalpine.ch website has some good footage of the terrain although it also includes the rather scary bits of the K42 and K78, which are more like fell than trail.