Are servos overkill?
Stepper motors are quite OK on the X3.
How fast do want to move and why.
When you are machining with a 1KW spindle steppers are more than powerful enough to shear off a 1/2" cutter, without losing steps.
Why complicate such a small machine. You will need a cabinet for the control gear instead of just a hump in the back.
As for rapid feed, the limits with most small cutters is their strength.
Do you really want the cutters to be bending much during cutting?
Even on wood, the SX3 with steppers can get be fed ultra fast with smoke coming off the cutter. Gives a nice burnt effect for engraving but hard on HSS cutters.
Bottom line. Do you NEED the speed.
I slowed mine so my brain can keep up with it.
If it had a tool changer, and was rushing around like a mad ant, then you might gain a bit of time. Have a coffee while it is working.
If you intend cutting lots of air speed is a definite advantage.
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.