I used to have that on a bike, I also had the opportunity to test ride the proto GT LTS that was built around such system (Bradley Mc Gee also had a Gitane Time Trial bike built for it, he unfortunatelly never used).
It works fine as long as you're the lucky winner of the "central valve" lottery.
I mean, this central valve either leaks air like a cow eating fresh green grass or remains quiet like a good Japanese geisha. :roll:
When it works, it's really cool, it shifts like your system is electrically driven. But after 400 shifts, forget it, back to the pit for a good pump session.
The system itself is a real tech beauty, was hand produced one by one in a special dust free zone of the Sakai factory. Actually 2500 pieces were produced beg 2000, but only 800 were sold worldwide, the rest got destroyed.