Many language learners just want to talk. They think that if they just talk they will improve. In my experience just talking is not enough. Talking is like playing the game of language learning. In a way it is the reward. It is why we do the other things like read, listen, write and accumulate words and phrases. We work hard to acquire more and more effective language tools so that when we talk we can express ourselves more accurately and more naturally.
Just talking is good practice……. at talking. However, conversing in a foreign language, while fun, is also a little stressful. It is not the ideal place to learn new words and phrases. It is a great place to confirm your knowledge of words and phrases that you have already learned.
Conversation class can be time consuming and expensive. It can also become quite boring if the conversation is forced. Like everything you do in language learning, it is best when it is meaningful and real. Conversation is a most effective learning activity if it is combined with other activities.