I've used its python bindings. I've been quite pleased with how well it works, honestly. I wrote some software for a client with multiple radio stations. It's a service that listens to one web stream per station and shoots the client an email/text if it detects problematic audio (e.g. static, silence, etc.). Some of the stations are talk and others are music, so it needed to be robust. Aubio made it really easy to test different detection algorithms, and its documentation was tremendously helpful. IRC room was active as well when I had questions.

aubio is the one python library I found that provided a ready-to-use pitch model, which I used for a simple script to listen for my doorbell. This worked much better than the more common approaches I saw elsewhere on the internet that did simple frequency detection.