I have the X2 with the MT3 spindle. The only tools I have which use this spindle is a set of ER collets and a holder for them, and a couple finger collets. I'm only using one of them for all my tools, as I have made 30 tool holders for diffenet sizes.
I can only see one advantage with the MT3. It has more clamping force, but this can also become a bit of a problem. If you get moisture in there and it starts to rust, it can be impossible to get out again (the collet or tool) |