Hehe, I know it will sounds a bit like “bragging” but I’m very aware of the fact that they are probably a lot of people on this forum with a better computer than mine, so it’s not bragging, it’s only about how impressed I am by Z-Brush (and paying my respect to the developers)
I got the components I needed to upgrade my computer yesterday (motherboard, 12GB of memory and a i7 980x)
I haven’t had time to really use Z-Brush in it yet, but after activating zbrush, since it was open there I decided to see what it can handle 
Starting with the base poly-sphere it went up to a bit over 26 millions poly and remained PERFECTLY responsive. When I clicked on the sphere after subdividing it, it halted for about a second (I guess some sort of caching) and after that, it was as responsive as a 2000 polygons model, amazing !!!
Pixo guys and girls, you will never stop to amaze me 
Jean-Luc