I would go back to hard lines in a heartbeat. I get much better schedules with hard lines (Aspen). The best part is you at least know what the options are. Sure, with pbs you could have a lot of options for bidding your schedule but CN pairings will ruin that. Hard lines never plopped a CN pairing right over the block of days off you needed for the month.
PBS works great in theory, then again, so does communism.

Sorry I'm a noob. What exactly is a hard line?

Hard line is a full schedule for the month that you bid on, the CO publishes the hard lines and you take the good and the bad and pick a entire schedule for the month.

Using a system like PBS all of the trips are available and you put together the trips you want to build a month's schedule(in theory).

I always get what I want (weekends/holidays off) in PBS, as long as I'm bidding 50% or better. But that's only because I went to great lengths to learn every in-and-out...not all of which are documented in writing, to really master it you need to talk to people who know what they're doing. But I also know how to write software.

As others mentioned it's very complicated and non-intuitive and does not fully respect seniority. If you're really good at it you can get more than your seniority deserves. But if you're not to good at complex logic, you're along for the ride.