Consuming immersive content over a browser is possible due to libraries such as WebGL, WebXR and Three.js. 360° videos, however, are very large in size, and high definition content can cause buffering events even in environments with high bandwidth. Immersiveness is further achieved in 360° content delivery with the addition of ambisonic audio, which indicates the source of sound, according to head tracking of users, in the 3-D space. In situations where video quality needs to be reduced due to network constraints, ambisonics can help increase user-perceived quality. This paper introduces a study of user experience with 24 participants located in various countries considering multiple quality levels of audio and video. An artistic- oriented platform for opera delivery is also described, in the context of the European Horizon 2020 TRACTION project.