If you want domestic upgrades it is worth it. Yes, GUCs and RUCs can be used but PMs can get RUC, although my experience is limited on these issues. I have never waited for hours at any level. If it situation is that bad but PMs (because of systemic IROPS) it will be bad for everyone but less bad for DMs. Some agents go the extra mile but I think the caller is somewhat in control of that.