I have a Mahlkonig K30. I bought it 2nd hand some months ago for less than $1k (a bargain for a 2 year old grinder). I installed new burrs which cost approx $150 from a supplier in Sydney, but it didnt really need them. It is my favourite grinder. Although it is very large (with a 3kg hopper that I dont use), very heavy, and very fast (a double shot in approx 5 secs). I usually have no static or clumping issues. I use it at work as my main grinder, and use Rocky for decaf. As you can see from my sig I have some other grinders as well. What would you like to know specifically?