In my particular case, the postmaster is part of the problem, and doesn't really care too much about anything but the policy, even when it means mail is being refused delivery. The oversight office complains that this branch doesn't pick up the phones - and places where they are asked to contact you about a problem, they do not. So yeah, depends totally on the branch, but they seem to know they have immunity.

I have very good luck with UPS. And again, I think that depends on the driver/route/branch/etc.

I used to use DVD service a lot at my old address and it was great, I wouldn't attempt it right now.