I have both griffon and jester schizos on two pairs of skis, as well as some regular jesters on my pow skis. IMO if you ski both park and all mountain regularly- they are worth it. My daily driver is the ON3P JMO- which is a pretty versatile ski. But with the schizo they can function as a pretty darn good park ski, and a decent pow ski as well- all by going from center mount to back 4-6 cm for pow. A lot of time I will only change the mount position at the beginning of the day, depending on the snow conditions. Sometimes at lunch. But I've been really glad I had them many days. Really improves the performance of the skis in specific applications- i.e. pow, trees, jumps, rails, moguls etc- I find I like difference positions for most all of them. That's me.
I don't notice the weight- they are about as heavy as pivot 18s, so not bad. As a pure park binding I wouldn't recommend, but for someone who actually does everything they are awesome. I'm a big guy and ski really hard, never had any durability issues after 2 seasons.
And people say they never get around to moving them- well IMO that's stupid. Literall take 30 seconds at lunch or whatever- skis are already off, just keep a screwdriver in your backpack or go to a tool bench. Instantly go from morning pow ski to afternoon park ski.