Monoprice Select IIIP Plus - Best speed settings and speeding up prints
In my experience a print speed of 50-70mm/s is ideal. Even if you set the speed to 150mm/s the print head still changes directions often and rarely will have enough time to accelerate from 0->150 before changing direction again. 

Some more effective ways of speeding up prints is to adjust


Layer height
Infill percentage (15-25% for regular prints, more if they need to be more sound)
Supports
Number of shells, etc