Already OK.
The machine given it's spindle speed and rapids is a nice balance between speed and stiffness.
You can make things jerk around more quickly and you will just start using the whole thing as a big spring as you change directions.
You are usually limited feed speed wise by the size of the cutters used.
Only if you increased it to above 25000 rpm would the extra snappy servos be of any use.(nuts)
The steppers are fine. Only bad programming requires you to cut air at supersonic speeds.
Because there is no auto tool changer, higher speeds are a bit like trying to hitting a golf ball with a cricket bat.:withstupi
Super X3. 3600rpm. Sheridan 6"x24" Lathe + more. Three ways to fix things: The right way, the other way, and maybe your way, which is possibly a faster wrong way.