There is no vacation touch provision in a PBS system. ASA has combatted this with language that allows you to maximize your days off in a vaca month while getting paid more, and not having the system put trips up against your vacation days. We also have more ability to drop trips into open time. This will accomplish the same thing.
Almost all other airlines have PBS now! Delta, American, CAL, UAL, Skywest, Comair, Pinnacle, Mesaba, Mesa all have this. I'm not sure about American or Southwest and some others, but it is becoming industry standard. If you know anything about negotiating it will be hard to convince an arbitrator or NMB panel that you refuse to negotiate this provision in your contract when nearly everybody else has it. Not to mention, the system ASA is getting is as good as or better than most everybody elses! That is a losing fight. If XJT is bought and absorbed into ASA, you WILL have PBS. It is not as bad as you think....