I know its wrong to choose because both suck, but I'll say stutter. Not being able to get words out of your mouth because you block all the time on nearly every word is a special kind of hell. I feel robbed of the ability to speak, like a mute at times. My teacher has a lisp, and while it may sound weird at times, atleast he can talk fluently. Again I'm not trying to gatekeep, but just my 2 cents.