I steered clear of the reverse cycle as my neighbour got one installed last summer;
Its just him in the house and he only used it when really needed etc - his power bills were $500-600 bimonthly over summer. Stuff that!
As long as your outlets, unit and ducting are sized correctly, an evap system will maintain sufficient airflow to not make the house seem like a 'swamp'. Instead it feels like living near the coast.