Update after 4 months: big savings on utilities, working great!
"Update to my first review.
I now have three full months of utility bills to review since installing this unit. Highest temp so far mid-80s (it's just barely spring in NC) and lowest temp is 7 degrees. We've had a very warm month and a very (VERY!) cold one. System has performed beautifully and cut my overall utility bills by almost 1/2! I'm on-track for this system paying for itself in just 13 months.
Full output down to 5 degrees F is a bold claim, and most heat pumps shut down the compressor at around 37 degrees. I was able to test this winter when we saw an outdoor low of 7 two nights in a row with a high of only 15-18. That's *unusually* cold for my area, but even with it bone-chilling cold outside, the system was giving me 75 degree air at my floor registers. Not blazing hot, but enough to keep us cozy.
The onboard software seems to be very intelligent about defrost cycles, only running them when necessary. I suspect there is a humidity gauge built into the outdoor unit. Defrost cycles are interesting -- The system simply reverses into "cool" mode for a few minutes, extracting a small bit of heat from inside the house to dump to the coils outside, melting any accumulated ice! Once cleared it reverses back to heat mode and continues."J_Turner - Highseer Store