Small burrs are preheating your coffee and brewing starts in the grinder
If you're a mazzer fan like me, try to go straight to 83mm and find the Major.
After some two years of lazy searching in local marketplace I've got one like new for 250€ and grind quality significantly better than my SJ. Comparing both with stock new burrs.

Dear borrik, I am sure that both the Major and Super Jolly are better than the stock Mini, but I cannot see how this statement can make sense: "Small burrs are preheating your coffee". After each run, the grinder would have ample time to cool down, as long ad you're not in a commercial environment. This would be a good reason for having a Mini for decaf in old school cafés, to not over-heat it by heavy action. At home, short runs with a minute pause should really be anough to keep burrs relatively cool???

JaBK, you could feel grounds heat up even via simple finger test after single run... Mazzer mini is a beautiful sweet grinder anyways

For Major I've started to roast the beans a bit darker because acidity raised with bigger burrs for me.