I've more or less decided on an Am.Std. Heritage series 14 13 SEER as a replacement unit and I'm wondering if I should take the Air-Tite VS handler or go with a single speed (if the unit will deliver 13 without one, it may be that I have to have VS). Assuming this is an option, I know that humidity control and lower energy consumption are factors to consider, but I'm not finicky about the former, my current ancient equipment works quite well for me and I don't believe energy savings with VS has a very short payback. Is there anything else I am missing? Thanks.