If you are happy at that then fine but 6 metres a minute over a bed length of this size doesn't give you much time to hit the E-stop.
Another point is that Mach is more happy at lower kernel speeds less chance of errors and the base 25K is plenty for mills etc.

The high speeds were brought in for routers and such with servo motors that require 2,000 to 4,000 steps per rev against steppers at 200 steps [ in full steps ] these were running out of steam.

You don't really achieve much on stepper driven machines as the stepper drivers are the choke point and get egg bound way before the set maximum.