I heard that IELTS is being zoned out soon. With that being said, I gave the TOEFL and it was indeed very difficult because you will have to say everything within 30 seconds or something, I remember a time limit being there. It was indeed very strenuous for me. I also heard talking to an actual person will always be more beneficial because they will know that you do know English but you have a stutter. In the case of TOEFL's computer version, that cannot be guaranteed because many people who are given low speaking scores are typically those who don't know English very well and most stutters sound like those inexperienced English speakers. There is a high risk of you being classified with a lower score. I got a speaking score of just 20. I couldn't get into many Canadian universities because I think they required 23 and above and some even required 25 and above. Thankfully, I got into UPenn in the USA where they don't have minimum scores but just a guideline of how your total score should look like. Also, if you have time, TOEFL offers stuttering people extra time to complete their speaking assessments but you will have to complete and send them the required documentation. I didn't do that because of my lack of time. All the best!