High Side Switch Implementation (Active-High)
It will work okay. 

The speed switching off will be much slower than switching on because the 10K resistor has to supply the ~6nC of gate charge on the p-MOS transistor. Maybe 10's of microseconds, but that should be okay at relatively low current- if you refer to the SOA curve. And relatively infrequent switching (not many kHz PWM). 

Another possible gotcha is that if the switch is activated with the 5V power rail lower than normal then it's possible for the p-channel MOSFET to turn partially on and damage or unsolder itself. If you are driving it with a processor that has  brownout reset and can verify that the pin goes low or high impedance under reset conditions it should be fine. 

Edit: You might also want to add a diode from the output to ground in case there is significant inductance in (or in the wires to) the load. The slow 'off' switching will help with this, but with enough inductance the drain could go far enough below ground to avalanche the 30V output MOSFET.