In this market I would take as many measures as I can to get as many buyers as possible into your home. Try to understand the magnitude of what is going on in this day and age.

To remedy your concerns I would recommend the following; Rather then having a Sentrilock box put on your home, go ahead and purchase a combo lockbox for 30 bucks at home depot. Have your realtor put in the showing instructions that when someone wants to see your home, they call the listing agent. When the listing agent gets a call, they call you. You give the listing agent the combo, the listing agent gives you the appt time and calls the other agent with the combo.

After the showing you then change the combo. This gives you the security you need but also lets the home get shown as much as possible.