If you had this problem in a piston twin provided you could reduce the RPM to no more than 10% overspeed I would definitely leave the engine running. Any useful power is better than no power at all, plus you still have redundancy with vacuum supply, electrical and possibly hydraulic power.
This statement is too simple. If the overspeed is caused by oil pressure problems to the hub you may lose your only chance of feathering if you delay. Not all multis feather automatically with loss of oil pressure and if the engine stops rapidly the feather locks may engage prior to it getting to a full feathered position.
The cause and remedy to a propeller overspeed is related to the pitch control mechanism, not necessarily the engine. Many engines have different propeller and hub options which can vary greatly in how they go about their business. How the mechanism operates may be very different for the same engine installation. One prop may have oil pressure one direction with a spring/aerodynamic forces opposing (not so bad if the spring moves it coarse), whilst the next installation has oil pressure moving the blade in both directions (can be very bad if oil is lost without pitch-locks, especially if the prop is capable of reverse pitch). Some may have pitch locks, fixed stops, counterweights, emergency feather pumps/accumulators, engine cut-out limits or no real protection for excessive overspeed.
The point is that you need to know your particular powerplant and how it operates to sucessfully deal with these types of emergencies. Be aware of any unusual indications or operation of the engine that would lead to a sudden overspeed situation and follow the correct aircraft procedure to deal with the situation as early as possible.