If humidity is an issue and you want to go with the VisionPro, I'd look into the 8321 model, with humidistat. Essentially the humidistat is an overcool feature, in that it allows the cooling cycle to run a few degrees below setpoint in order to accomplish dehumidification. It will not allow the system to continue running if dehumidification has not been met but the temperature has gone below setpoing as far as allowed. In other words it will not override setpoint and just keep cooling until the humidistat is satisfied, which could be never on a high humidity day with constant door opening and closing going on in the house.
To me the proper overall approach to humdity control in a muggy climate is a tight house kept at a positive pressure with decent insulation, with an ERV to maintain fresh air without upsetting humidity levels. Add to this a form of modulation or capacity control for the HVAC system to deal with days where humidity levels are high but sensible heat loads are lower and you have a system that will perform well under a wide variety of conditions.
Psychrometrics: the very foundation of HVAC. A comfort troubleshooter's best friend.