I saw one apartment complex this year that had a twist on the package robot concept -- there's an iPad at the door of the mail room, and you type in the code from your package, the iPad takes your photo and then unlocks the mail room door using a solenoid.
The UPS guy? Scans the barcodes on the packages, then wheels them in and drops them off on cheap metal shelves inside -- no need to pay an employee to manage the mail room 24/7. More residents/packages? Just buy a few more shelves. Resident wants to pick up a package as soon as Amazon buzzes them? No problem. Resident wants to pick up at 2am? Great.
The only problem is you have to trust your neighbors to not steal your packages.