Wow. That is still pretty slow spinup. Glad to hear it is much better than before though. At least it's usable at 7 seconds. Just put a delay in and off you go.
On the mill I built using a treadmill motor and Surplus Center controller, it is less than a second to spin up to 6600 RPM. Motor actually doing about 4000. Maybe two to three seconds to stop. It's at full speed before the coolant hits the part.