My understanding of PBS is that pairings will remain the same. Having spoken with several ex Skywest pilots and others who've had PBS, 90%+ of them (at least the ones I've met) do not want PBS, especially knowing this management. This just has been my experience so take it for what it's worth.
PBS can be good if the pilots have control of it (ie. VX, Delta, etc.) but good luck with that here at Alaska. I was told at Skywest, the company can/will force a trip on your line on short/high season months even if you didn't bid it, regardless of seniority. There was a term for this but I can't recall at the moment. At least with line bidding, you know what you are getting. As it stands now, scheduling can only force a trip on your line (bid block holder) if your line drops below the month's minimum guarantee (vacation months & months with trip illegalities). Even in this case, the pilot can choose which trip to pickup after open flying has been awarded.