I was considering Sofdent appointment reminder after leaving convention on friday, but after reading all these post I am sticking with Demandforce. It has everything everyone is complaining about on the other systems. Thank you all for the information.
Since my original reply, I have learned that LightHouse will send a pre-med reminder on a patient by patient basis. For patients that require pre-med, we just have to add user code P to the patient.