Next onto the M4 Doserless, .......... This grinder does clump a fair bit. WDT is your friend here. Using WDT, I was able to get a comparable shot to my own M4. You definitely need some mechanism to break up the clumps otherwise - channel city!
Finally, onto the Mazzer Mini E, ......... Well, I have to say, definitely less clumping than the M4. ........ I have to admit to being a bit disappointed here because I do think I finally got a better shot out of the Mazzer than my M4. A little more, well defined, maybe less "muddled", not sure of the words but I did think the Mazzer had the best tasting shot