From what I've seen (in a non-airline environment), ASAP is a mess that basically gives the company something to point at and say "hey look, we're doin somethin!" rather than substantive (and expensive) changes that would be effective (autopilots in helicopters, mandated, regular, actual-IMC training for VFR programs, perhaps even multi-engine/multi-pilot mandates like they have in Cannuckistan).
That said, in a more general sense, my only real problem with Unions in our rarefied, sanctified "Profession" is that they're paper tigers under the RLA/NLRB/etc. Until you suckers stop voting for one statist clown in order to stop the other statist clown, I can't see how Unions are going to do much to improve either Safety or QOL. *shrug*. I'd love to be wrong, but like, how long has it been since anyone negotiated a vast improvement in a pilot contract?