Hi,
yes, some motion controllers have closed loop operation, some of them pretty damn good at it too, they tend to be rare
and expensive.
If you really want a closed loop spindle an AC servo and matching drive are hard to beat. The loop is closed by the drive.
The manufacturer has both the servo and drive to design and play with and usually do a very good job; that you and I
would struggle to match even with a really great (expensive) motion controller.
As tweakie has pointed out many have used lesser performing control loop strategies and achieved good results at a lesser
price. I bought a second hand Allen Bradley servo (1.8kW 6 Nm 3500 rpm) and drive, I luv it.
Craig