I've been buying B fares internationally now for the past year even if it's not the least expensive fare because, if it's going to waitlist, I feel a lot better knowing I'm on top of the waitlist fare-wise. And, I've had an upcoming nail-biter SFO-FRA/LHR-SFO that only just cleared for the outbound, two days prior-- but I strongly believe that my fare class is what helped me along (vs. having a W/V/Q or something lower and therefore up against more people). Indeed, I've found B fares often clear to NC pretty quickly after purchase. Take some solace that pretty much the only ones who can beat you out now are UGS.