The biggest difference between digital and analog tape machines concerns storage flexibility. Unlike a tape recorder, digital machines can erase one message without disturbing others on the machine. This allows important messages to be kept without cluttering the machine with less relevant messages.

A second advantage of digital machines is that sound quality can be better than with tape devices. Tape machines all suffer from some level of background hiss, particularly with the outgoing message, while digital machines typically offer a much cleaner-sounding message. However, be aware that digital technology does not guarantee good sound. Some digital recorders use cheap microphones or very low sampling rates. In many cases, a cheap digital machine may sound worse than a tape machine.

A third advantage of digital units is reliability. Since these units have no moving parts, they tend to be very sturdy. In contrast, tape-based machines are relatively complex, and tend to break down after a few years of use.

One disadvantage of digital machines concerns power failure. If the power goes out, digital machines can lose all their messages unless there is a battery backup feature.