i run a makergear m2 and like jolly i run it from .1-.25mm. usually almost everything is at .15. rick the owner of makergear has a yoda head that he printed on one of their machines that was done at .02mm. yeah thats not a typo. i personally dont know how he did it. i have seen real close up shots of it and man is it smooth. it was just something for them to do to say that it could be done but those layer heights arent practical at all and take a really good machine and alot of tuning in the software.