In apartments in other U.S. cities I've had the opposite experience. USPS has been reliable, because the USPS mailbox array for the past two buildings I've lived in has included both the usual small boxes for everyone's mail, plus a few large boxes used to deliver packages. USPS sticks my package in one of the empty boxes, and slips the key into my mailbox. No problem at all for unattended delivery, at least for small- and mid-sized packages (obviously they can't deliver a TV there). But UPS and FedEx don't have any system like that installed, so they either leave you a "sorry we missed you" note, or just leave the package sitting somewhere unsecured.