So, it heats water with a heat pump. That means it will be cooling off the surrounding air (in your basement or wherever your WH is located.)
It costs about $1600.
When the heat pump can't keep up with demand, it goes into "regular" resistance-element electric heating mode. Cha-ching!
I wonder how well the heat-pump function works when temps are cool (say, in a 55 degree basement or a 40 degree garage in the winter?)
I guess it might make sense if you have to cool your home most of the year anyway, but if you are heating the area where the water heater is located, it won't save much at all. It will be a net negative (by far) if this space heating is done with expensive sources (electric resistance, propane, etc.)
You'd have to run the numbers for your particular situation (especially the price of NG, the amount of hot water you use, your electric rates, your heating and cooling degree days, etc), but I think most folks with moderately-priced NG available will find it cheaper to use that. Plus, the technology of modern NG high-efficiency water heaters are well developed, this is generation one for the GE unit.
If you've got NG available, maybe consider a modern high-efficiency NG unit. Because they use a fan to expel the relatively cool exhaust gases, they can be located in areas that would be a problem for a conventional NG water heater. If you've got an exterior wall nearby, the PVC intake and exhaust pipes can go right through it to the outside. No need for a roof penetration or other hassles.