At Swissair it was introduced for flightdeck crew about 1 1/2 year ago. There was a agreement, that there is no influence of seatindex after use of the PBS (or optimizer).
At the beginn we had a lot of troubles and there are still some points to be adjusted, but for the crews, I think, it is a big improvement in lifestyle, even if I would have to work a little more I still would prefer th new system!
Just to give a clarification: The PBS is only one part, which enables the crew to bid for certain flights, stations, off-days, partners and so on. The other part is the optimizer, which is working out the best combimations of rotations.