I tried the voice mode for 30 minutes, and it was surprisingly natural. It corrects your pronunciation when you make mistakes, and if you ask to change the topic, it switches right away.
Downside: The conversation depth is shallow. For example, if you say, "Let's discuss climate change," it just repeats surface-level content.
Still, considering the cost of a tutor, the value for money is unbeatable. Even just 10 minutes a day is worth trying.