I thought I'd revive this thread since I am now the owner of an AO Smith HPWH (PHPT60, 60 gallon heat pump/electric water heater). My father and I installed it last weekend and it has been running nicely thus far. It is too early to figure out any cost savings yet.
I found a place in NJ online selling it for $1036 including shipping/tax (of which there wasn't any). My local utility will rebate me $500 (right away) and the Fed will provide an energy credit of $300 (to be filed next year). For those not familiar with a heat pump, it sucks in ambient air, removes the heat (and uses it to heat the water) and moisture (condenses and drains out) and then blows out cool, dry air. My location is somewhat confined and I've determined that I need to pick up AO Smith's outlet duct kit and redirect that cool, dry air to ensure it is not being sucked back into the inlet side. That is another $120. I had about $100 in various parts (copper pipe/fittings, pvc, electrical box/outlet/wire, valves, pipe insulation, etc.). I figure I have another $450 to make back to break even on this deal. I don't imagine that will take longer than a couple of years. I get 10 years on the tank and parts. AO Smith's customer service has been pretty good as I had some issues. One was the display panel that they forgot to plug into the circuit board. One was a wire I cut that I shouldn't have (for the float switch on my condensation pump) that they helped me diagnose via feedback from the display panel. I also have very small bubbles of paint (i.e. rust forming under the paint) on the outer "tank" or sleeve of the water heater here and there. Since this isn't the actual tank, I'm not too worried but there are some issues with quality control for the painting, I think.
I'll post some pics later of my install.