The gate voltage plateaus somewhat above the threshold voltage as the gate charges/discharges. A typical non-logic level MOSFET will have a plateau about one third of the 10V gate-fully-on voltage, about 3 or 4V. The exact voltage of the plateau varies with device and drain current and voltage though.
Notice that driving through a resistor means that as the plateau is closer to 0V than 10V, it will discharge more slowly than charging (if plateau at 3V, then there is 7V across resistor when charging, -3V across the resistor when discharging, over twice as slow to switch off.
For this reason you'll see MOSFET driver chips usually provide more current sink than source since they want to correct this imbalance of switching times. My favorite MOSFET driver is probably the MIC4422 which can source or sink upto 9A, Yes, 9A... It makes it a handy MOSFET half-H-bridge in its own right (in fact I've used it as a class-D audio amplifier output stage!).