Awesome! 4.5 stars w/ pluses and minuses.
First, if you are buying this for energy savings alone, if you have natural gas, think again. It may be the lowest operating cost per year water heater out there but the difference in operating cost with natural gas between this heater and a regular energy star non-condensing heater which cost $1200 or so less just for the water heater (not even considering installation costs which are substantially higher for the westinghouse heater) your gas savings based on national averages, is only 30-50 dollars per year. For propane, your savings would be substantially higher since propane costs more.
Second, I'll speak to the quality of materials--exceptional. This heater has a stainless steel tank, therefore, it is much more durable than the regular non-condensing water heaters out there which have either glass coated steel or baked enamel linings. Too, regular tanks have anode rods which sacrificially corrode to protect the tank from corroding. Taken together, these two things help prevent your tank from rusting and ultimately leaking. But very few people flush their water heaters every six months as recommended to remove sediment and mineral buildup and even fewer inspect or replace their anode rods. I am not an engineer, however, I know it has to be cheaper (but not better) to build water heaters with steel tanks with anode rods and glass line them than to build them with stainless steel tanks otherwise, there would be more stainless water heaters out there. Why aren't there more stainless steel tanks? For the same reason people don't install slate roofs which last 100 years. Obviously, people aren't willing to pay for them. They ignore their water heater until it busts and they haven't planned or budgeted for a new one.
Third, this water heater performs like a champ. I mean BOOM, it performs. A regular 50 gallon water heater produces about 41 gallons of hot water an hour at 90 degree rise and they typically have first hour ratings in the 75-80 gallon range. If you love long, hot firehose showers (which are practically regarded as a right of citizenship in the US) or if you have a large jacuzzi or garden tub (as I do) or a fancy shower, teenagers, or a large family, a normal 50 gallon water heater, is a pretty lame performer. This westinghouse heater will knock your socks off producing 100-200 gallons of hot water in an hour and it recovers in minutes and it is capable of producing a near continuous flow. Nothing can beat that but a tankless heater but they will break the bank and you have to delime them once a year or they don't last.
Fourth, this thing is expensive. $2,000 to buy and I had to run the vent pipe 21 feet out the side of my house which wasn't cheap. But, you most likely won't have to upgrade your gas service or run a larger gas line as you would with a tankless water heater since this thing is only 75,000 BTUs instead of 160,000 to 200,000 BTUs for a tankless.
What should you do? Depends on your circumstances. Money is a factor obviously for most of us but my question is why do we have disposable water heaters which we spend $1,100 on national average to replace every 8-10 years? It seems Westinghouse has the answer to that merry go round replacement but the premium is over $1500-$2000 or more over the average. Like most things in life good things are seldom cheap and cheap things are seldom good. Is it worth it? For me it is because I love the hot water particularly in the winter when I want to roast in a hot tub and I like knowing the thing uses less gas than anything else out there. I just hope the thing lasts. The tank should for certain. And I think this thing has been made long enough to get most of the operational bugs out of it.
Pros: bang up performance, hot water super fast, stainless steel tank, appearance, durability and quality of materials seems high, energy cost very low;
Con: ROI, not so much, more complexity, venting requirements which adds to the cost of most installations and the heater itself is very expensive.