I've only lived in one apartment that had such a system, and it was probably the nicest solution to the problem. The only issue was that it took awhile for the

I've only lived in one apartment that had such a system, and it was probably the nicest solution to the problem. The only issue was that it took awhile for the landlord to change the phone number for our unit to ours, and similarly when we moved out - I kept getting phone calls for that door for months.