I find C.Ai better actually because it is good at waiting for you to finish speaking, you can even tell it to wait a certain amount of seconds before responding. Meanwhile, gpt advanced voice function keeps interrupting me all the time to the point that I'm getting actually frustrated and angry. As soon as I voluntarily pause or block, it will start replying as if I have finished speaking and no amount of feedback/commands can make it listen longer. Also do your own research and studies on stuttering techniques, the ones these bots provide are not nearly as useful as others that you can find in books and/or from speech therapists.