I'm currently obtaining quotes for a heat pump, and had a question for current owners. What kind of HSPF rating do you have, and approximately how low in temp does your unit operate until? If you were to get a new unit, what would you look for this time around? I'm looking at units in the 16 SEER/8.5-9 HSPF range, but also the 18 SEER/11 HSPF range. The cost for me is about double when jumping to the higher end model as it requires me to get a new furnace/fan coil along with the outdoor unit (variable speed compressor paired with variable speed fan in the furnace). The lower end units are single speed compressors and work fine with my existing fan coil. I'm more interested in longer term savings with better efficency & lower operating temperatures for winter. The cut off for the lower end models is -15 (I suspect -20 for the higher end models). And I requested a quote on one of the Misubishi units that is good for -30. I'm expecting that one to not be cheap at all.