As I've said before when the topic arose, I'm definitely in favour of a (good quality, nicely installed and protected by bash gaurd) hydraulic clutch. I've had two clutch cable failures in as many years on my 90/6, many days ride from home- the first one two days before christmas. First time I had a spare cable with me, second time I clutchless shifter for a while and got a cable from a friend. Both times were headaches.
In the whole time I've owned it I've had zero problems with my old master cylinder or calipers.
Those magura kits sound pretty reliable... time will tell.
If the bike in question didn't already have a hydraulic system that required maintenance, then yeah, if you were so inclined, I'd say KISS- but to me as it is I think... what is one more hydraulic system to maintain? I'd bleed my brake when I did my clutch, and do my clutch when I did my brake, and they'd both be happier for it. If the clutch failed, I'd just be back to clutchless shifting like when your last cable fails.
I'd really like to hear the short and longer term feedback on this unit.
I've put an ASV clutch perch on my G/S- it really feels fantastic so I am in no rush to change it, but sometime down the line I'm inclined towards hydraulic. I got no luck with cables.