How smart are the chatbots?
They are pretty smart. They are based on a model that has been specifically trained for language processing with massive amounts of data. They can understand irony and sarcasm. They understand context. They know a lot about the world. That said, they might not know much about current events.
Are the chatbots sentient?
They are not, but they are capable of rational, logical thinking.
How will talking to the chatbots improve my Spanish?
Practicing with a chatbot is a great way to practice your sentence-building skills in Spanish. You can try to speak in different tenses, and ask and answer questions that are similar to the ones you would see in a real conversation with a human. They are engaging, and always available. Here's a paper that outlines the benefits.
Do AI robots want to dominate the world?
Sara or Peter don't, but we're not that sure about Luis. That said, he doesn't have access to weapons, and his area of influence is limited to the Spanish students he talks to.