The main difference between Bose SoundTouch and a soundbar is that the SoundTouch is an older version, while the soundbar is a newer version with additional features. The Soundbar 700, which is the upgraded version of the SoundTouch 300, offers enhanced features such as Alexa and Google Assistant compatibility, Airplay 2 compatibility, and an advanced microphone array. It also comes at a higher price compared to the SoundTouch 300. The soundbar provides a sleek and modern design with exceptional sound quality. It supports eARC, has room correction, and EQ presets. Both the SoundTouch and the soundbar offer immersive sound, but the soundbar offers more advanced features and a better overall experience.