I've seen exactly two setups with Syncro II that shifted well: a Pinarello built from scratch by a bike shop in 1992, and a used setup I bought knowing that it worked well for the previous owner. One was always pretty good, but not perfect and the other was a real learning experience, as bike mechanics my brother-in-law took it to said it needed this and that and it really didn't need anything. It ended up on a Canopus build and he's been fine with it.

Everything else was a real PITA.