Ask HN: Experience with AI to learn a foreign language?

I have become motivated to pick up another language. (I'm going to follow through with it this time...probably) Research and experience suggest that conversation with feedback is the fastest way to improve language skills. It occurred to me that an AI could be well suited to that task, conversing and learning during my commute.

I see that there are already a few options available for this. Does anyone have any experience with these to offer a recommendation?

Hearsay and wild speculation is welcome.